Some people have been clamoring for cross-game chat on the PlayStation 3 for while now. Well, you can stop crying for it because it's not going to happen. The reason,
as IGN shows, is that the PS3 lacks the necessary ram to allow this feature. Once a game gets a hold of that ram on the PS3, it doesn't give it back.
Now, the Vita has double the ram of the PS3 so it does have the cross-game chat capability the PlayStation 3 lacks. So if you want that feature on a Sony platform, the Vita is the way to go.