This is my first post. I'm just asking who thinks there. Would be a Co-op expansion for Skyrim? As a friend and I were thinking there should be one.

Multiplayer won't be added to Skyrim. This is something that really needs to be incorporated into the engine from the very beginning, adding it after the fact would require re-doing large amounts of existing thread.

http://www.gamesas.com/index.php?/topic/1239188-official-tes-multiplayerco-op-thread/. You're welcome to post in there, but please make sure you read the opening post first, it has important ground rules.