My original thought was that this was based on the kernel of Morfik (compiler/JST, etc.), which would be a wise decision since that is a really solid piece of art. Now, as Alex pointed out, the About box does not credit Morfik in any way, which is puzzling. They may probably have a special contract -- I am guessing here... ...I suppose we will learn this sooner or later. Anyone any real facts?
OTOH you are right: Morfik in its entirety is a much more complete product with all the IDE/debugging/profiling/visual design tools/included server side components, etc., so I think the two may become symbiotic: for smaller Java-only projects, where visual editing and all the other 21st century IDE stuff is not needed GWT will be perfect, and when it comes to the other languages and/or more complete UIs then Morfik can be used.
It will be interesting to see how the two will complement each other... If one looks around can see now a trend that many AJAX UI toolkit vendors (either OS or closed) are trying to create common widget sets -- this is an area where GWT/Google and Morfik could form a leading role and come up with some common standards (Backbase, Prototype, etc. come to my mind too) -- this would be a win for us application developers, although IMHO how all these AJAX UI widget toolkits will differentiate themselves in the long run is something I don't see.