Lowered the priority of the old command handler event because a number of plugins were using this event incorrectly. A new event, the command preprocesser event, has replaced the previous function of the original command event.

src/main/java/org/bukkit/event/Event.java

@@ -178,6 +178,13 @@ public abstract class Event {
          */
         PLAYER_COMMAND (Category.PLAYER),
 
+        /**
+         * Called when a player early in the command handling process
+         *
+         * @see org.bukkit.event.player.PlayerChatEvent
+         */
+        PLAYER_COMMAND_PREPROCESS (Category.PLAYER),
+
         /**
          * Called when a player leaves a server
          *

src/main/java/org/bukkit/event/player/PlayerListener.java

@@ -43,9 +43,7 @@ public class PlayerListener implements Listener {
     }
 
     /**
-     * Called when a player attempts to use a command. Avoid using this
+     * Called when a player attempts to use a command.
-     * when possible -- it won't be removed, but this is not how you
-     * handle commands.
      *
      * @param event Relevant event details
      */
@@ -53,6 +51,15 @@ public class PlayerListener implements Listener {
     public void onPlayerCommand(PlayerChatEvent event) {
     }
 
+    /**
+     * Called early in the command handling process. This event is only
+     * for very exceptional cases and you should not normally use it.
+     *
+     * @param event Relevant event details
+     */
+    public void onPlayerCommandPreprocess(PlayerChatEvent event) {
+    }
+
     /**
      * Called when a player attempts to move location in a world
      *

src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java

@@ -150,6 +150,11 @@ public final class JavaPluginLoader implements PluginLoader {
                     ((PlayerListener)listener).onPlayerCommand( (PlayerChatEvent)event );
                 }
             };
+        case PLAYER_COMMAND_PREPROCESS:
+            return new EventExecutor() { public void execute( Listener listener, Event event ) {
+                    ((PlayerListener)listener).onPlayerCommandPreprocess( (PlayerChatEvent)event );
+                }
+            };
         case PLAYER_CHAT:
             return new EventExecutor() { public void execute( Listener listener, Event event ) {
                     ((PlayerListener)listener).onPlayerChat( (PlayerChatEvent)event );