I'm releasing this now as I probably won't be working on it much longer. There is a new version of Box2D coming out that changes the very foundations of the engine, so if I want the new features I'll have to start over on the extension (which might be a good thing as it is very messy at the moment...)
I've fixed all known bugs (I think) and added a few new features since the last beta release. If there still happens to be some bugs left I'll look into it, but don't expect any new features to be added.
You can get it here
