PC.IGN has posted their preview of ION Storm's upcoming Unreal-engine RPG Deus Ex. The preview is chock full of info from the design team, including this bit, which is the first I've heard of a possible multiplayer portion of the game:

While the answer to the multiplay question was "no way in hell" five months ago, the team at ION has reevaluated the situation and it looks like Deus Ex will indeed ship with a multiplayer component after all. "Even if all we can do is deathmatch, then you bet your ass we're gonna do it," Warren brashly told us. The team already has deathmatch up and running, and are considering even more options. However, the main focus for Deus Ex is still on the single player experience, so they've made no promises as of yet.