Splinter Cell: Conviction will feature a co-op multiplayer mode when it is released early next year.
Ubisoft is apparently going to give UK based PC Zone magazine a hands on demo of the co-op mode plus a new unannounced mode. CVG posted a story stating that the magazine teased the story in their latest issue. Very few details have been revealed at this point. The new Splinter Cell: Conviction issue will be released on December 23rd so we will have to wait until then to get more details. The last time co-op made an appearance in the franchise was in Splinter Cell: Chaos Theory way back in 2005.
Splinter Cell: Conviction is going to be released on February 23rd for Xbox 360 and the PC.