the reason sony hasnt included cross game chat yet is because the ps3 has RAM problems. you lag opening up the in-game XMB when you play black ops... imagine trying to play black ops and your ps3 being connected to 3 servers at one time? (gayarch server, sony server, and possibly extra server for chat). the psVita probably reduced the RAM needed for certain games to be played which would allow cross game chat.
oh and this obviously patches QA flagging. if you have a QA flag enabled console... DO NOT UPDATE TO 3.66. let some guinea pig do so first.