Having received a lot of positive feedback for my last post, I finally found the time to make the source code available. You can find it in the SVN repository of the GMFTools project.
I have put the installation instructions here.
Note that this is proof-of-concept code rather than production quality. See my previous post for implementational details. Also note that two open bugs
currently limit the fun a little bit, but we're at least working on the Xtext part.