Which game? The only one I can think of that's coming out very soon is the Neverwinter Nights Shadows of Undrentide expansion. If that's the case, then it's single-player with online capabilities.
Wait, do you mean
Dungeons and Dragons Heroes ? It just suddenly popped into my head. It has a four player multiplayer, so I guess that's what you must be talking about.
Just click the link above to check it out.