In case you've missed it, take a look at: http://java.sun.com/developer/technicalArticles/J2SE/peabody/
Very good step, in my opinion. I hope it gets attention of the best-of-breed developers. It will probably be a big challenge to keep the compatibility, on the other hand the JDK team definitely has lots of experiences with keeping it, so it might work well. Our QA team
will be thinking of you!