If only it was that easy. There are 2 attacks.
1: Oracle are attacking the underlying use of a VM with patents, changing source language makes no difference. That's the patent attack and luckily it doesn't seem to be going well for Oracle. Working around the patents might not have a crippling cost, having to compile to machine code would be very bad news.
2: Copyrights. Having failed miserably to find anything but de minimus direct copying (of the 8 test files that don't ship with Android devices, weren't even used and were removed from the source tree), Oracle are inventing brand new law to try and attack the use of Java's library environment. The problem being that Sun didn't own the source they use and API's aren't currently copyrightable. I say invent, actually they're just recycling the paperwork from SCO vs the World (same lawyers, same crackpot thinking, same result?).
However, if they succeed on the library front, changing language or VM becomes irrelevant. Simply calling the system libraries would be infringement, regardless of implementation. If Oracle succeed the entire software industry is in severe danger so don't expect that to be allowed to happen.
I'm not sure Oracle are even trying to claim the Java language, something Sun very publicly gave away long ago.