Category 'B' license the best compromise
Simon Phipps has laid out quite a good explaination of open source licenses in his white paper at http://blogs.sun.com/roller/page/webmink?entry=open_source_licensing_paper
In my opinion, his conclusion that category 'B' licenses, like CDDL or MPL, strike the best balance is correct.
What I want out of an open source Java platform, is a truly interoperable platform that nevertheless allows the extra libraries developed under the JCP and other standards-like environments to be added, without necessarily mandating that those other libraries must use any specific license.
This would solve my companies needs, while allowing us to contribute to an open source java platform. For me, the core java platform (in J2ME) is a non-differentiator - I need to have it, but so does everyone else. Interoperability is key, and a category B open source license for Java will, in my opinion, provide that.