Since my last post I've been working mainly on user documentation and jUnit tests. I managed to create an extension point for my generator. It lets you change not only the look of generated code, but also the way the templates are handled (so you can for example add your own tokens). I also tried to add toString() generation to code completion proposals, but there are some problems I can't solve right now. This and the fact that JDT guys are rather skeptic about this feature made me postpone the work on it.
So the project is now finished and waiting to be reviewed by JDT team. I can't wait for the results. If everything goes fine, it will be added to Eclipse 3.5. Meanwhile, as I have nothing better to work on (and official end of GSoC is August 18th), I'll try to make the generator a separate plugin so that it can be used with earlier versions of Eclipse.