Index: src/applications/maniphest/controller/ManiphestSubpriorityController.php
===================================================================
--- src/applications/maniphest/controller/ManiphestSubpriorityController.php
+++ src/applications/maniphest/controller/ManiphestSubpriorityController.php
@@ -41,28 +41,18 @@
       $after_sub = null;
     }
 
-    $new_sub = ManiphestTransactionEditor::getNextSubpriority(
-      $after_pri,
-      $after_sub);
-
-    $task->setSubpriority($new_sub);
-
-    if ($after_pri != $task->getPriority()) {
-      $xactions = array();
-      $xactions[] = id(new ManiphestTransaction())
-        ->setTransactionType(ManiphestTransaction::TYPE_PRIORITY)
-        ->setNewValue($after_pri);
-
-      $editor = id(new ManiphestTransactionEditor())
-        ->setActor($user)
-        ->setContinueOnMissingFields(true)
-        ->setContinueOnNoEffect(true)
-        ->setContentSourceFromRequest($request);
-
-      $editor->applyTransactions($task, $xactions);
-    } else {
-      $task->save();
-    }
+    $xactions = array(id(new ManiphestTransaction())
+      ->setTransactionType(ManiphestTransaction::TYPE_SUBPRIORITY)
+      ->setNewValue(array(
+        'newPriority' => $after_pri,
+        'newSubpriorityBase' => $after_sub)));
+    $editor = id(new ManiphestTransactionEditor())
+      ->setActor($user)
+      ->setContinueOnMissingFields(true)
+      ->setContinueOnNoEffect(true)
+      ->setContentSourceFromRequest($request);
+
+    $editor->applyTransactions($task, $xactions);
 
     return id(new AphrontAjaxResponse())->setContent(
       array(
Index: src/applications/maniphest/editor/ManiphestTransactionEditor.php
===================================================================
--- src/applications/maniphest/editor/ManiphestTransactionEditor.php
+++ src/applications/maniphest/editor/ManiphestTransactionEditor.php
@@ -16,6 +16,7 @@
     $types[] = ManiphestTransaction::TYPE_PROJECTS;
     $types[] = ManiphestTransaction::TYPE_ATTACH;
     $types[] = ManiphestTransaction::TYPE_EDGE;
+    $types[] = ManiphestTransaction::TYPE_SUBPRIORITY;
     $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
 
@@ -58,6 +59,8 @@
       case ManiphestTransaction::TYPE_EDGE:
         // These are pre-populated.
         return $xaction->getOldValue();
+      case ManiphestTransaction::TYPE_SUBPRIORITY:
+        return $object->getSubpriority();
     }
 
   }
@@ -79,6 +82,7 @@
       case ManiphestTransaction::TYPE_DESCRIPTION:
       case ManiphestTransaction::TYPE_ATTACH:
       case ManiphestTransaction::TYPE_EDGE:
+      case ManiphestTransaction::TYPE_SUBPRIORITY:
         return $xaction->getNewValue();
     }
   }
@@ -102,7 +106,6 @@
     return parent::transactionHasEffect($object, $xaction);
   }
 
-
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
@@ -147,10 +150,39 @@
         // These are a weird, funky mess and are already being applied by the
         // time we reach this.
         return;
+      case ManiphestTransaction::TYPE_SUBPRIORITY:
+        $data = $xaction->getNewValue();
+        $new_sub = $this->getNextSubpriority(
+          $data['newPriority'],
+          $data['newSubpriorityBase']);
+        $object->setSubpriority($new_sub);
+        return;
     }
 
   }
 
+  protected function expandTransaction(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+
+    $xactions = parent::expandTransaction($object, $xaction);
+    switch ($xaction->getTransactionType()) {
+      case ManiphestTransaction::TYPE_SUBPRIORITY:
+        $data = $xaction->getNewValue();
+        $new_pri = $data['newPriority'];
+        if ($new_pri != $object->getPriority()) {
+          $xactions[] = id(new ManiphestTransaction())
+            ->setTransactionType(ManiphestTransaction::TYPE_PRIORITY)
+            ->setNewValue($new_pri);
+        }
+        break;
+      default:
+        break;
+    }
+
+    return $xactions;
+  }
+
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
@@ -159,7 +191,19 @@
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
-    return true;
+    $should_mail = true;
+    if (count($xactions) == 1) {
+      $xaction = head($xactions);
+      switch ($xaction->getTransactionType()) {
+        case ManiphestTransaction::TYPE_SUBPRIORITY:
+          $should_mail = false;
+          break;
+        default:
+          $should_mail = true;
+          break;
+      }
+    }
+    return $should_mail;
   }
 
   protected function getMailSubjectPrefix() {
@@ -305,10 +349,7 @@
   }
 
 
-  public static function getNextSubpriority($pri, $sub) {
-
-    // TODO: T603 Figure out what the policies here should be once this gets
-    // cleaned up.
+  private function getNextSubpriority($pri, $sub) {
 
     if ($sub === null) {
       $next = id(new ManiphestTask())->loadOneWhere(
Index: src/applications/maniphest/storage/ManiphestTransaction.php
===================================================================
--- src/applications/maniphest/storage/ManiphestTransaction.php
+++ src/applications/maniphest/storage/ManiphestTransaction.php
@@ -12,6 +12,7 @@
   const TYPE_PRIORITY = 'priority';
   const TYPE_EDGE = 'edge';
   const TYPE_ATTACH = 'attach';
+  const TYPE_SUBPRIORITY = 'subpriority';
 
   public function getApplicationName() {
     return 'maniphest';
@@ -85,6 +86,8 @@
           return false;
         }
         break;
+      case self::TYPE_SUBPRIORITY:
+        return true;
     }
 
     return false;
Index: src/applications/project/controller/PhabricatorProjectBoardController.php
===================================================================
--- src/applications/project/controller/PhabricatorProjectBoardController.php
+++ src/applications/project/controller/PhabricatorProjectBoardController.php
@@ -96,8 +96,10 @@
     foreach ($columns as $column) {
       $panel = id(new PHUIWorkpanelView())
         ->setHeader($column->getDisplayName())
-        ->setHeaderColor($column->getHeaderColor())
-        ->setEditURI('edit/'.$column->getID().'/');
+        ->setHeaderColor($column->getHeaderColor());
+      if (!$column->isDefaultColumn()) {
+        $panel->setEditURI('edit/'.$column->getID().'/');
+      }
 
       $cards = id(new PHUIObjectItemListView())
         ->setUser($viewer)
Index: src/applications/project/controller/PhabricatorProjectMoveController.php
===================================================================
--- src/applications/project/controller/PhabricatorProjectMoveController.php
+++ src/applications/project/controller/PhabricatorProjectMoveController.php
@@ -72,8 +72,31 @@
       $column_phid,
       $edge_phids);
 
-    // TODO: We also need to deal with priorities, so far this only gets stuff
-    // in the correct column.
+    if ($after_phid) {
+      $after_task = id(new ManiphestTaskQuery())
+        ->setViewer($viewer)
+        ->withPHIDs(array($after_phid))
+        ->requireCapabilities(array(PhabricatorPolicyCapability::CAN_EDIT))
+        ->executeOne();
+      if (!$after_task) {
+        return new Aphront404Response();
+      }
+      $after_pri = $after_task->getPriority();
+      $after_sub = $after_task->getSubpriority();
+
+      $xactions = array(id(new ManiphestTransaction())
+        ->setTransactionType(ManiphestTransaction::TYPE_SUBPRIORITY)
+        ->setNewValue(array(
+          'newPriority' => $after_pri,
+          'newSubpriorityBase' => $after_sub)));
+      $editor = id(new ManiphestTransactionEditor())
+        ->setActor($viewer)
+        ->setContinueOnMissingFields(true)
+        ->setContinueOnNoEffect(true)
+        ->setContentSourceFromRequest($request);
+
+      $editor->applyTransactions($object, $xactions);
+    }
 
     return id(new AphrontAjaxResponse())->setContent(array());
   }
Index: src/view/phui/PHUIWorkpanelView.php
===================================================================
--- src/view/phui/PHUIWorkpanelView.php
+++ src/view/phui/PHUIWorkpanelView.php
@@ -53,15 +53,20 @@
           $footer_tag);
     }
 
-    $header_edit = id(new PHUIIconView())
-      ->setSpriteSheet(PHUIIconView::SPRITE_ACTIONS)
-      ->setSpriteIcon('settings-grey')
-      ->setHref($this->editURI);
+    $header_edit = null;
+    if ($this->editURI) {
+      $header_edit = id(new PHUIIconView())
+        ->setSpriteSheet(PHUIIconView::SPRITE_ACTIONS)
+        ->setSpriteIcon('settings-grey')
+        ->setHref($this->editURI);
+    }
 
     $header = id(new PhabricatorActionHeaderView())
       ->setHeaderTitle($this->header)
-      ->setHeaderColor($this->headerColor)
-      ->addAction($header_edit);
+      ->setHeaderColor($this->headerColor);
+    if ($header_edit) {
+      $header->addAction($header_edit);
+    }
 
     $body = phutil_tag(
       'div',