With there being 12 players, I'd expect three teams of four. I don't have the game yet, but plan on getting it over break (tomorrow-Monday) with the headset. I won't be able to play it though, if you look at my sig (bottom part).
Goldeneye 007 FC: Level 34 156714564753 - [SA]DarkWolf/Byrne+/Omega[DG] The Wii has not been playing Wii games as of March 4, 2010
6 players per team is fine by me. 5v5 in Black Ops didn't work for me on certain maps like Array because it took forever to find anyone. But the maps and team size in Conduit 2 are good as long as you have a full lobby.