Picked up Mercenaries 2 yesterday and found out there is NO split screen co-op even though the Amazon description mentioned there was. Looking elsewhere I found that co-op splitscreen was not mentioned either so it must be just an Amazon typo.
Also, similar to my problems with Battlefield: Bad Company, I am not able to connect to the EA Servers which means I can't play co-op via XBox Live either(this seems to be a fairly common problem with EA games though..even after opening the ports and such).
Mind you I am having fun with the game so far. Though I do wish you could duck or somehow take cover. And the vehcile driving seems a bit too sensitive.
I had planned on picking this up with or without co-op, but just wanted to warn anybody who was planning on playing splitscreen with their friend.