We weren't supposed to break things *that* hard. Plugins still need to update but here's a TEMPORARY fix.

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

@@ -2,6 +2,7 @@
 package org.bukkit.event.player;
 
 import org.bukkit.event.Listener;
+import org.bukkit.plugin.AuthorNagException;
 
 /**
  * Handles all events thrown in relation to a Player
@@ -16,6 +17,8 @@ public class PlayerListener implements Listener {
      * @param event Relevant event details
      */
     public void onPlayerJoin(PlayerJoinEvent event) {
+        onPlayerJoin((PlayerEvent)event);
+        throw new AuthorNagException("onPlayerJoin has been replaced with a new signature, (PlayerJoinEvent)");
     }
 
     /**
@@ -24,6 +27,8 @@ public class PlayerListener implements Listener {
      * @param event Relevant event details
      */
     public void onPlayerQuit(PlayerQuitEvent event) {
+        onPlayerQuit((PlayerEvent)event);
+        throw new AuthorNagException("onPlayerQuit has been replaced with a new signature, (PlayerQuitEvent)");
     }
 
     /**
@@ -49,6 +54,8 @@ public class PlayerListener implements Listener {
      * @param event Relevant event details
      */
     public void onPlayerCommandPreprocess(PlayerCommandPreprocessEvent event) {
+        onPlayerCommandPreprocess((PlayerChatEvent)event);
+        throw new AuthorNagException("onPlayerCommandPreprocess has been replaced with a new signature, (PlayerCommandPreprocessEvent)");
     }
 
     /**
@@ -65,6 +72,8 @@ public class PlayerListener implements Listener {
      * @param event Relevant event details
      */
     public void onPlayerTeleport(PlayerTeleportEvent event) {
+        onPlayerTeleport((PlayerMoveEvent)event);
+        throw new AuthorNagException("onPlayerTeleport has been replaced with a new signature, (PlayerTeleportEvent)");
     }
 
     /**
@@ -163,9 +172,9 @@ public class PlayerListener implements Listener {
     public void onPlayerBucketEmpty(PlayerBucketEmptyEvent event) {
     }
 
-    // Prevent compilation of old signatures TODO: Remove after 1.4
+    // TODO: Remove after RB
-    @Deprecated public final void onPlayerQuit(PlayerEvent event) {}
+    @Deprecated public void onPlayerQuit(PlayerEvent event) {}
-    @Deprecated public final void onPlayerCommandPreprocess(PlayerChatEvent event) {}
+    @Deprecated public void onPlayerCommandPreprocess(PlayerChatEvent event) {}
-    @Deprecated public final void onPlayerTeleport(PlayerMoveEvent event) {}
+    @Deprecated public void onPlayerTeleport(PlayerMoveEvent event) {}
-    @Deprecated public final void onPlayerJoin(PlayerEvent event) {}
+    @Deprecated public void onPlayerJoin(PlayerEvent event) {}
 }

src/main/java/org/bukkit/event/server/ServerListener.java

@@ -2,6 +2,7 @@
 package org.bukkit.event.server;
 
 import org.bukkit.event.Listener;
+import org.bukkit.plugin.AuthorNagException;
 
 /**
  * Handles all miscellaneous server events
@@ -13,6 +14,8 @@ public class ServerListener implements Listener {
      * @param event Relevant event details
      */
     public void onPluginEnable(PluginEnableEvent event) {
+        onPluginEnable((PluginEvent)event);
+        throw new AuthorNagException("onPluginEnable has been replaced with a new signature, (PluginEnableEvent)");
     }
 
     /**
@@ -21,6 +24,8 @@ public class ServerListener implements Listener {
      * @param event Relevant event details
      */
     public void onPluginDisable(PluginDisableEvent event) {
+        onPluginDisable((PluginEvent)event);
+        throw new AuthorNagException("onPluginDisable has been replaced with a new signature, (PluginDisableEvent)");
     }
 
     /**
@@ -31,7 +36,7 @@ public class ServerListener implements Listener {
     public void onServerCommand(ServerCommandEvent event) {
     }
 
-    // Prevent compilation of old signatures TODO: Remove after 1.4
+    //  TODO: Remove after RB
-    @Deprecated public final void onPluginDisable(PluginEvent event) {}
+    @Deprecated public void onPluginDisable(PluginEvent event) {}
-    @Deprecated public final void onPluginEnable(PluginEvent event) {}
+    @Deprecated public void onPluginEnable(PluginEvent event) {}
 }

src/main/java/org/bukkit/event/vehicle/VehicleListener.java

@@ -1,6 +1,7 @@
 package org.bukkit.event.vehicle;
 
 import org.bukkit.event.Listener;
+import org.bukkit.plugin.AuthorNagException;
 
 /**
  * Listener for vehicle events.
@@ -74,8 +75,10 @@ public class VehicleListener implements Listener {
      * @param event
      */
     public void onVehicleUpdate(VehicleUpdateEvent event) {
+        onVehicleUpdate((VehicleEvent)event);
+        throw new AuthorNagException("onVehicleUpdate has been replaced with a new signature, (VehicleUpdateEvent)");
     }
 
-    // Prevent compilation of old signatures TODO: Remove after 1.4
+    // TODO: Remove after RB
-    @Deprecated public final void onVehicleUpdate(VehicleEvent event) {}
+    @Deprecated public void onVehicleUpdate(VehicleEvent event) {}
 }

src/main/java/org/bukkit/event/world/WorldListener.java

@@ -2,6 +2,7 @@
 package org.bukkit.event.world;
 
 import org.bukkit.event.Listener;
+import org.bukkit.plugin.AuthorNagException;
 
 /**
  * Handles all World related events
@@ -29,6 +30,8 @@ public class WorldListener implements Listener {
     * @param event Relevant event details
     */
     public void onWorldSave(WorldSaveEvent event) {
+        onWorldSave((WorldEvent)event);
+        throw new AuthorNagException("onWorldSave has been replaced with a new signature, (WorldSaveEvent)");
     }
 
     /**
@@ -37,9 +40,11 @@ public class WorldListener implements Listener {
      * @param event Relevant event details
      */
     public void onWorldLoad(WorldLoadEvent event) {
+        onWorldLoad((WorldEvent)event);
+        throw new AuthorNagException("onWorldLoad has been replaced with a new signature, (WorldLoadEvent)");
     }
 
-    // Prevent compilation of old signatures TODO: Remove after 1.4
+    // TODO: Remove after RB
-    @Deprecated public final void onWorldLoad(WorldEvent event) {}
+    @Deprecated public void onWorldLoad(WorldEvent event) {}
-    @Deprecated public final void onWorldSave(WorldEvent event) {}
+    @Deprecated public void onWorldSave(WorldEvent event) {}
 }

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

@@ -258,7 +258,7 @@ public final class SimplePluginManager implements PluginManager {
                     if (plugin.isNaggable()) {
                         plugin.setNaggable(false);
                         server.getLogger().log(Level.SEVERE, String.format(
-                            "Nag author: %s of %s about the following:",
+                            "Nag author: '%s' of '%s' about the following: %s",
                             plugin.getDescription().getAuthors().get(0),
                             plugin.getDescription().getName(),
                             ex.getMessage()