GWT is great except for that pesky little Java problem.

First Java is really the only language option in the current language options. During the Google I/O keynote GWT actually mentions a spring tool that generates boiler plate code. This is ultimately my problem with Java it is not expressive enough. With some exceptions (low level languages like C) this is a FAIL mode for any language. Just can't beat the GWT UX though from performance to maintainability.