Of course there have also been some minor ui improvements (e.g. for copy/paste and drag&drop of (rich) text), and a couple of fixes for bugs and crashes. All in all I think the new interface is really superior to the old one now, which is of course the least I wanted the achieve in this project.
That's all from this rather short report. There is not much use in describing the changes in detail, but I want to encourage everybody to have a look at the new interface (the code can be found at the gsoc2012 branch) and to let me know if there are any problems. Thanks :)