The product of this script is a working application with a server round trip that shows the power and simplicity of GWT RPC. Unfortunately, this project is chock full of comments and unnecessary code so much, that it is hard to see trees behind forest! I cleaned this many times to figure out simple things, but this time decided to drop it into the blogo-sphere so that other people could benefit as well.
I was able to reduce the amount of code to about 1/4th of the original, leaving the same functionality in place.
Here is the link: http://igorpolevoy.com/public/attach/GWT/test.zip