Hi Dustin,
Interesting approach, it looks good. Just recently I've blogged about
a very similar approach here:
http://oktech.hu/blog/2009/07/spring-gwt-integration-with-ease.html
It is not as polished as yours (especially in the documentation part),
but a few idea might be interesting for you:
As a developer who's seen several teams struggle with all the moving
parts involved in GWT on top of Spring, I've started a new project
(http://code.google.com/p/spring4gwt/) that will help tie several
things together.
First, it provides a simple exporter for Spring services directly
accessible
