> Sun doesn't permit the patent license to go to people who build out
> distributions of JavaSE without including all classes specified under
> java.* and javax.*.
Sun was on very dicey legal ground here: GPL doesn't permit the enforcement of additional restrictions via patents (this is what the implicit patent grant is all about). Section 7 (of GPLv2) is very clear what happens when you take enforcement actions on this: the licence terminates and the software becomes undistributable ... for everyone. Sun, since it sat outside of the GPL ecosystem,might have been able to weather this consequence but Oracle is a major participant in that ecosystem.
If it came to a court battle on this point over some GPL derivative of Java, I'm pretty sure the entire GPL ecosystem would be lining up behind whoever had been threatened with a patent suit. My point is that this is currently not happening for Google because they chose not to be part of that ecosystem.