First GWT 1.6 is available for download. Please see the official blog entry from Google here.
Second big annoucement for GWT is that the Google Apps Engine now supports Java. One thing to be aware of is that google has said that they are only allowing the first 10,000 developers. Better sign up fast. Here is the link to signup.
The also ask that you provide feedback, here is that link.
To find out more please see the official blog post from Google here on Google App Engine supporting Java.
For those of you using Eclipse for Java development (and I highly recommend you use it) there is now a GWT/App engine plugin for Eclipse.
For more information on the plugin see this Blog post.
The quick start guide to install the GWT/Google App Engine Eclipse plugin is here.
If you are already an eclipse user and know how to install plugins here are the shortcuts you need:
Eclipse 3.3 (Europa)
Eclipse 3.4 (Ganymede)