Like I indicated in another post, there is nothing to stop Microsoft from having their own "windows-only" forked version of Java. And nothing to stop from the GNU/Debian crowd to have their own "puritanical" version. And nothing to stop from IBM to have their own "enterprise-ready" version of Java.
Java is a trademark. What will stop these gratutious forks is that they can not call it Java if they have modified and redistributed Sun's codebase on their own.