Weak argument
I don't like Sun/Oracle's "field of use" restrictions - surely, if I want to play Pong on a Cray or shoehorn Ubuntu onto an old 386, that's my problem, whether it works or not?
Having said that, "it's freely available so you can't enforce copyright" is a really, really dumb argument. Will they be redistributing modified copies of the Windows 8 preview release? That's free, too, but I suspect Microsoft might just get all lawyered up about that idea! Even open-source/free-software doesn't mean you can do what you like regardless of licence - the FSF of all people should be on board with that distinction.
I hate the idea of software patents and of trying to restrict use of a protocol or interface (look at the Linux kernel fiasco with BitKeeper?) - but it does look as if (a) the room wasn't quite 'clean' after all (Sun stuff slipping in) and (b) Sun/Oracle have patents which cover things Android does, at which point no clone, clean-room or not, is safe.
With hindsight, and given their love of Java, maybe Google should have bought Sun themselves...