The PSN version will get some exclusive content and features, but the only announced improvement at this time is the ability to join games in progress. Like the Xbox 360 and PC releases, the PSN version will have "numerous multiplayer maps, seven game types, four co-op missions and literally trillions of weapon combinations."
Three new trailers have also been released, which can be found below.
I still can't believe they didn't have dedicated servers on the pc version and that
you cannot join games already in progress.
Who needs dedicated servers when you have THE POWER OF GFWL!
Shame that they aren't releasing the new content on PC/360 though.