It can be nice to integrate video in GWT vthrough VLC, the famous video/audio platform.
This tutoral explains ho to do this.
Jetty and GWT
"The Google Web Toolkit allows Ajax applications to be developed in java code using the traditional UI widget paradigm. The toolkit includes support for RPC, but not for comet style Ajax push.
Unfortunately GWT has not made it easy to use continuations within their RPC mechanism. Firstly they catch Throwable, so the Jetty RetryException is caught. Secondly they have made most of the methods on the GWT servlet final, so you cannot fix this by extension...."