Want to buy Dragon Age 2 on Steam? Hold your horses. It's not there anymore.
There's been no official explanation for the removal, but Eurogamer note that it coincides with the release of the Dragon Age 2: Legacy expansion pack, which is available to buy now from an in-game store.
If you already own a Steam copy of Dragon Age 2, it'll still work fine, it's just been removed from the Steam shop. It's still available to buy from Direct2Drive , GamersGate and EA's own Origin store.
Crysis 2 was also removed from Steam recently. EA later said that it was Valve who made the decision to pull the game, and attributed the decision to a DLC agreement with Direct2Drive.
EA have also been busy promoting Origin. Star Wars: The Old Republic will only be available digitally through EA's store, and current indications suggest that Battlefield 3 will be an Origin exclusive as well. We'll have to wait and see what happens with other big EA releases like Mass Effect 3.