There are some issues with DWR 2.x, notably WOOKIE-222, that are fixed in the 3.x release. We should update DWR, or investigate a replacement framework for comet/websocket support such as Atmosphere.
Provide an improved method for providing server-side messaging between widgets in Wookie
Replace dwr.xml with annotations
"Session Error" dialog for each widget appears in tomcat 7 (using the WAR build)