Pardon my ignorance, but what kind of infrastructure do you need for running GWT? It pretty much means running your own (dedicated) servers, right? (For example, I understand that Google's App Engine does not yet support it!)
Actually, Google's AppEngine is nicely integrated with GWT. Check out the Google Eclipse Plugin (http://code.google.com/eclipse/) -- even if you're not using eclipse, this will give you a good idea.
It's also worth pointing out that a compiled GWT application can be deployed entirely statically. The Java RPC system does require a servlet container, but there are lots of other ways of talking to servers (JSON[P], XHR, etc).