Adult Swim claimed to get the rights to three shows, so i've heard. My prediction is that one of those is definitely going to be Code Geas Season Three (i forgot the real name, but it starting in Japan like later this year). The other will definitely be Full Metal Alchemist Brotherhood. And for the last show I'd place my bets on Soul Eater.
I never considered One Piece, but it has a chance I suppose. I would think they would pick up series like Bakuman too or something, but that also doesn't come out for awhile, like code geass. so maybe they still will get them and code geass isnt one of the three they got now, and there is still one open spot. so who knows