diff --git a/resources/celerity/map.php b/resources/celerity/map.php
index d09165b13a..73daecb1fd 100644
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -8,7 +8,7 @@
 return array(
   'names' => array(
     'core.pkg.css' => 'a419cf4b',
-    'core.pkg.js' => '400453e4',
+    'core.pkg.js' => '57dff7df',
     'darkconsole.pkg.js' => 'e7393ebb',
     'differential.pkg.css' => '2de124c9',
     'differential.pkg.js' => '64e69521',
@@ -487,9 +487,9 @@ return array(
     'rsrc/js/core/behavior-object-selector.js' => '49b73b36',
     'rsrc/js/core/behavior-oncopy.js' => '2926fff2',
     'rsrc/js/core/behavior-phabricator-nav.js' => '56a1ca03',
-    'rsrc/js/core/behavior-phabricator-remarkup-assist.js' => 'ecddcbe2',
+    'rsrc/js/core/behavior-phabricator-remarkup-assist.js' => 'b60b6d9b',
     'rsrc/js/core/behavior-refresh-csrf.js' => 'ab2f381b',
-    'rsrc/js/core/behavior-remarkup-preview.js' => 'f7379f45',
+    'rsrc/js/core/behavior-remarkup-preview.js' => '4b700e9e',
     'rsrc/js/core/behavior-reorder-applications.js' => '76b9fc3e',
     'rsrc/js/core/behavior-reveal-content.js' => '60821bc7',
     'rsrc/js/core/behavior-scrollbar.js' => '834a1173',
@@ -640,7 +640,7 @@ return array(
     'javelin-behavior-phabricator-notification-example' => '8ce821c5',
     'javelin-behavior-phabricator-object-selector' => '49b73b36',
     'javelin-behavior-phabricator-oncopy' => '2926fff2',
-    'javelin-behavior-phabricator-remarkup-assist' => 'ecddcbe2',
+    'javelin-behavior-phabricator-remarkup-assist' => 'b60b6d9b',
     'javelin-behavior-phabricator-reveal-content' => '60821bc7',
     'javelin-behavior-phabricator-search-typeahead' => '048330fa',
     'javelin-behavior-phabricator-show-older-transactions' => 'dbbf48b6',
@@ -662,7 +662,7 @@ return array(
     'javelin-behavior-releeph-preview-branch' => 'b2b4fbaf',
     'javelin-behavior-releeph-request-state-change' => 'a0b57eb8',
     'javelin-behavior-releeph-request-typeahead' => 'de2e896f',
-    'javelin-behavior-remarkup-preview' => 'f7379f45',
+    'javelin-behavior-remarkup-preview' => '4b700e9e',
     'javelin-behavior-reorder-applications' => '76b9fc3e',
     'javelin-behavior-reorder-columns' => 'e1d25dfb',
     'javelin-behavior-repository-crossreference' => 'e5339c43',
@@ -1125,6 +1125,12 @@ return array(
       'javelin-request',
       'javelin-util',
     ),
+    '4b700e9e' => array(
+      'javelin-behavior',
+      'javelin-dom',
+      'javelin-util',
+      'phabricator-shaped-request',
+    ),
     '4e3e79a6' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1721,6 +1727,15 @@ return array(
       'javelin-dom',
       'javelin-util',
     ),
+    'b60b6d9b' => array(
+      'javelin-behavior',
+      'javelin-stratcom',
+      'javelin-dom',
+      'phabricator-phtize',
+      'phabricator-textareautils',
+      'javelin-workflow',
+      'javelin-vector',
+    ),
     'b65559c0' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1960,15 +1975,6 @@ return array(
       'phabricator-phtize',
       'javelin-dom',
     ),
-    'ecddcbe2' => array(
-      'javelin-behavior',
-      'javelin-stratcom',
-      'javelin-dom',
-      'phabricator-phtize',
-      'phabricator-textareautils',
-      'javelin-workflow',
-      'javelin-vector',
-    ),
     'edd1ba66' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -2005,12 +2011,6 @@ return array(
       'javelin-util',
       'javelin-reactor',
     ),
-    'f7379f45' => array(
-      'javelin-behavior',
-      'javelin-dom',
-      'javelin-util',
-      'phabricator-shaped-request',
-    ),
     'f7fc67ec' => array(
       'javelin-install',
       'javelin-typeahead',
diff --git a/src/applications/maniphest/application/PhabricatorManiphestApplication.php b/src/applications/maniphest/application/PhabricatorManiphestApplication.php
index c0d0a4d7ef..3fcbbf49f0 100644
--- a/src/applications/maniphest/application/PhabricatorManiphestApplication.php
+++ b/src/applications/maniphest/application/PhabricatorManiphestApplication.php
@@ -52,13 +52,6 @@ final class PhabricatorManiphestApplication extends PhabricatorApplication {
         'task/' => array(
           $this->getEditRoutePattern('edit/')
             => 'ManiphestTaskEditController',
-          'descriptionpreview/'
-            => 'PhabricatorMarkupPreviewController',
-        ),
-        'transaction/' => array(
-          'save/' => 'ManiphestTransactionSaveController',
-          'preview/(?P<id>[1-9]\d*)/'
-            => 'ManiphestTransactionPreviewController',
         ),
         'export/(?P<key>[^/]+)/' => 'ManiphestExportController',
         'subpriority/' => 'ManiphestSubpriorityController',
diff --git a/src/applications/maniphest/editor/ManiphestEditEngine.php b/src/applications/maniphest/editor/ManiphestEditEngine.php
index aac21ea7ac..b7e3cee965 100644
--- a/src/applications/maniphest/editor/ManiphestEditEngine.php
+++ b/src/applications/maniphest/editor/ManiphestEditEngine.php
@@ -156,7 +156,10 @@ final class ManiphestEditEngine
         ->setConduitDescription(pht('Update the task description.'))
         ->setConduitTypeDescription(pht('New task description.'))
         ->setTransactionType(ManiphestTransaction::TYPE_DESCRIPTION)
-        ->setValue($object->getDescription()),
+        ->setValue($object->getDescription())
+        ->setPreviewPanel(
+          id(new PHUIRemarkupPreviewPanel())
+            ->setHeader(pht('Description Preview'))),
     );
   }
 
diff --git a/src/applications/transactions/controller/PhabricatorApplicationTransactionRemarkupPreviewController.php b/src/applications/transactions/controller/PhabricatorApplicationTransactionRemarkupPreviewController.php
index 4ba8345d5c..2714be02c4 100644
--- a/src/applications/transactions/controller/PhabricatorApplicationTransactionRemarkupPreviewController.php
+++ b/src/applications/transactions/controller/PhabricatorApplicationTransactionRemarkupPreviewController.php
@@ -10,9 +10,9 @@ final class PhabricatorApplicationTransactionRemarkupPreviewController
   public function handleRequest(AphrontRequest $request) {
     $viewer = $this->getViewer();
 
-    $corpus = $request->getStr('corpus');
+    $text = $request->getStr('text');
 
-    $remarkup = new PHUIRemarkupView($viewer, $corpus);
+    $remarkup = new PHUIRemarkupView($viewer, $text);
 
     $content = array(
       'content' => hsprintf('%s', $remarkup),
diff --git a/src/applications/transactions/editengine/PhabricatorEditEngine.php b/src/applications/transactions/editengine/PhabricatorEditEngine.php
index 2e96e60dd0..041bb05393 100644
--- a/src/applications/transactions/editengine/PhabricatorEditEngine.php
+++ b/src/applications/transactions/editengine/PhabricatorEditEngine.php
@@ -962,6 +962,28 @@ abstract class PhabricatorEditEngine
       $header_text = $this->getObjectEditTitleText($object);
     }
 
+    $show_preview = !$request->isAjax();
+
+    if ($show_preview) {
+      $previews = array();
+      foreach ($fields as $field) {
+        $preview = $field->getPreviewPanel();
+        if (!$preview) {
+          continue;
+        }
+
+        $control_id = $field->getControlID();
+
+        $preview
+          ->setControlID($control_id)
+          ->setPreviewURI('/transactions/remarkuppreview/');
+
+        $previews[] = $preview;
+      }
+    } else {
+      $previews = array();
+    }
+
     $form = $this->buildEditForm($object, $fields);
 
     if ($request->isAjax()) {
@@ -998,7 +1020,8 @@ abstract class PhabricatorEditEngine
     return $controller->newPage()
       ->setTitle($header_text)
       ->setCrumbs($crumbs)
-      ->appendChild($box);
+      ->appendChild($box)
+      ->appendChild($previews);
   }
 
   protected function newEditResponse(
diff --git a/src/applications/transactions/editfield/PhabricatorEditField.php b/src/applications/transactions/editfield/PhabricatorEditField.php
index 9d1b976299..1216370819 100644
--- a/src/applications/transactions/editfield/PhabricatorEditField.php
+++ b/src/applications/transactions/editfield/PhabricatorEditField.php
@@ -14,6 +14,8 @@ abstract class PhabricatorEditField extends Phobject {
   private $metadata = array();
   private $editTypeKey;
   private $isRequired;
+  private $previewPanel;
+  private $controlID;
 
   private $description;
   private $conduitDescription;
@@ -251,6 +253,15 @@ abstract class PhabricatorEditField extends Phobject {
     return $this->commentActionValue;
   }
 
+  public function setPreviewPanel(PHUIRemarkupPreviewPanel $preview_panel) {
+    $this->previewPanel = $preview_panel;
+    return $this;
+  }
+
+  public function getPreviewPanel() {
+    return $this->previewPanel;
+  }
+
   protected function newControl() {
     throw new PhutilMethodNotImplementedException();
   }
@@ -285,6 +296,13 @@ abstract class PhabricatorEditField extends Phobject {
     return $control;
   }
 
+  public function getControlID() {
+    if (!$this->controlID) {
+      $this->controlID = celerity_generate_unique_node_id();
+    }
+    return $this->controlID;
+  }
+
   protected function renderControl() {
     $control = $this->buildControl();
     if ($control === null) {
@@ -308,6 +326,10 @@ abstract class PhabricatorEditField extends Phobject {
 
     $control->setDisabled($disabled);
 
+    if ($this->controlID) {
+      $control->setID($this->controlID);
+    }
+
     return $control;
   }
 
diff --git a/webroot/rsrc/js/core/behavior-phabricator-remarkup-assist.js b/webroot/rsrc/js/core/behavior-phabricator-remarkup-assist.js
index 293c44ed9b..9dabffeb10 100644
--- a/webroot/rsrc/js/core/behavior-phabricator-remarkup-assist.js
+++ b/webroot/rsrc/js/core/behavior-phabricator-remarkup-assist.js
@@ -254,7 +254,7 @@ JX.behavior('phabricator-remarkup-assist', function(config) {
     var value = area.value;
 
     var data = {
-      corpus: value
+      text: value
     };
 
     var onupdate = function(r) {
diff --git a/webroot/rsrc/js/core/behavior-remarkup-preview.js b/webroot/rsrc/js/core/behavior-remarkup-preview.js
index f703e56266..4e79c48b59 100644
--- a/webroot/rsrc/js/core/behavior-remarkup-preview.js
+++ b/webroot/rsrc/js/core/behavior-remarkup-preview.js
@@ -8,16 +8,26 @@
 
 JX.behavior('remarkup-preview', function(config) {
 
+  // Don't bother with any of this on mobile.
+  if (JX.Device.getDevice() !== 'desktop') {
+    return;
+  }
+
   var preview = JX.$(config.previewID);
   var control = JX.$(config.controlID);
 
   var callback = function(r) {
-    JX.DOM.setContent(preview, JX.$H(r));
+    // This currently accepts responses from two controllers:
+    // Old: PhabricatorMarkupPreviewController
+    // New: PhabricatorApplicationTransactionRemarkupPreviewController
+    // TODO: Swap everything to just the new controller.
+
+    JX.DOM.setContent(preview, JX.$H(r.content || r));
   };
 
   var getdata = function() {
     return {
-      text : control.value
+      text: control.value
     };
   };