Though this is very cool, there are inherent problems with the approach of generating JavaScript that runs your application. All inherent server-side dynamics are completely removed from this concept and have to be explicitly added specifically.
I'm also biased as I've been developing a far better solution (in my opinion of course) which you can see a very early sneak peak of here:
http://www.jseamless.orgThis actually solves a ton of other problems that the GWT doesn't even address (such as abstraction away from a specific UI implementation).
I'm curious if the AJAX done on jSeamless works on Konquerer....haven't actually tried it on a linux box yet.
-Matt Hicks