I think they will add the cross game voice chat. If ps2 emulation is done (which I doubt) there sure won't be trophies for any of those games.
Grief reporting would be good to have as well. Theres an awfully high number of people online playing games, with no desire to BE online playing games…douchebags. I tried playing nazi zombies online with randoms last night…woulda had more success putting my hand in the deep fryer.