Card Captors: There is a 6 volume manga that runs on after the main series called "master of the clow" they should do something with that.
Sailor Moon: afaik Sailor Stars (the last series) never aired outside Japan, but with the whole idea of guys turning into girls when they transformed, I don't think it'll happen.
Fruits Basket: my best friend's been going on about this one for years. I can't see them making any more, but it's a shame, as the top selling manga in the States, you'd think they would be able to make quite a lot off it.
Air Gear: Completely agree with whoever mentioned this one, the manga is fantastic.
Gakuen Alice: Again, manga almost finished now so if we're going to get another series of that, it will probably happen then. Again, I'm guessing not though.
FMA Brotherhood: I'm SO glad they made this series. Yes, the manga was better than the first series and so this was the release that should have happened originally.
I'm hoping for a second series of Saki, a third series of Tsubasa and, heaven forbid we might finally get the rest of Shana this year *fingers crossed*