I think Oracle would allow it if the price was right. The problem is that "one Java" probably means Java SE, which means you have to use bloat like JAR files and Swing/AWT, which would make Android less competitive with iOS.
Would it really help if someone paid $Nbn for the Java label for some snapshot of Harmony or whatever? Open source software (which is open in spirit, not just by name) is always a moving target. As soon as you fork it, it's no longer covered by the license. And when is it a fork, exactly?
I don't think anybody's talking about a snapshot. During the Sun/Google negotiations there was discussion of an ongoing partnership where Google would be forced to adopt new versions of Java as the JCP released them. Google didn't want the JCP backseat-driving Android, so they declined.
