I can't remember where I read it now, but reportedly the reason why Brown left Rihanna was because he had choked her out- she was unconscious. If that is true, it sounds to me like he was fleeing the scene of a crime. I bet he thought he killed her.
But, going on facts, he is charged with felony domestic assault. If he had assaulted or killed any other woman (like William Shatner, for example, that douchebag who drowned his olympic-swimmer wife in their backyard pool) then I think he'd get off.
He beat up Rihanna, though, who is the pop-star du jour... she reports that he's hit her before, and whatever happened, she's marked up enough that she can't be seen in public.
I think he actually will go to jail for this.
Unfortunately, he will probably serve all his time in protective custody. No ass-raping there.