http://code.google.com/appengine/
App Engine is unveiling its second language: Java. Today’s release includes an early look at our Java runtime, integration with Google Web Toolkit, and a Google Plugin for Eclipse, giving you an end-to-end Java solution for AJAX web applications. Our support for the Java language is still under development and we’re eager to get your help and input. For now, access will be limited to the first 10,000 developers who sign up, but we’ll be including more as soon as possible. Give it a try and send us your feedback.
(Thanks to @talios for this gem)