What does Oracle expect to gain?

Simple Reasoning and then, Complex?
A good summary. After several days of thinking about this I can only come to two conclusions, neither of which I like:
a) Oracle is realizing that mobile is strategic and has decided this is how they will get in on the action. They think it is much more important than Java. They will force Google to license Java from them and that way gain not only royalties, but actual control of Android.
b) This is purely about damaging Android. There is an agreement we know nothing about yet between Apple and Oracle that if Oracle takes down Android something will happen in return from Apple. They don't care if they win or lose, they just want to smash adoption of Android. It could as easily be a move from MS but it is hard to think past the bitterness and sense of betrayal expressed by Jobs about Android, or the frequently reported "close friendship" between Ellison and Jobs.
I wish these were conspiracy theories but I can't account for Oracle's willingness to detonate what is still an incredibly valuable Java asset any other way.
(Blog - Hacker News)

Google's response to Oracle suit

“We are disappointed Oracle has chosen to attack both Google  and the open-source Java community with this baseless lawsuit," a Google spokesperson said in an e-mailed statement. "The open-source Java community goes beyond any one corporation and works every day to make the Web a better place. We will strongly defend open-source standards and will continue to work with the industry to develop the Android platform.”