Playstation Allstars has been out for a while and there is most likely going to be a sequel. Obviously the single player needs the most impovements but there are a few multiplayer tweaks that would be good.
-1v1 ranked. They will most likely patch it into PSASBR but it should have been avalible at lanch
-Lobbies. For between 8-20 people, these make community night streams much easier and are a staple of fighting games.
-More instruction. The belt system should be explained in game, also a tutorial for online/custom matchea because some reviewers didn't even know you had the option to see the score
-Host Migration. Frankly I don't know if this is possible but if it is it should be in the next game.
-Theater mode/youtube upload. In Uncharted 3 you could upload matches to youtube from the game w/out a pvr. That should be in every game.
-More online trophies.The trophies in this game aren't hard they are just tedious, add some more online trophies!
-Call it Playstation All-Stars:Title Fight. This has nothing to do with multiplayer but who cares