Glad I read this, as I was planning to buy it. I still have the original installed and play from time to time, so I was hoping that they built a new MP platform.
Well, it has a new multiplayer platform, in the sense that multiplayer is now synced with Steam, instead of being through MSN Zone. Pretty much the only improvement is the ability to join up on your steam friends' games.
Really, if you only want to play SP games, then the original is good enough.