Haven't touched the multiplayer yet, but single player looks really damn good. If I was to give a comparison, I'd say that the screen shot posted up there looks like a wii port of the game compared to how good the single player looks.
I still have some problems with it in areas, but I blame the engine for that. In general I think UE3 is unable to make natural looking environments look, well, natural. Even so the caves look really damn good, but there is a section later on with ice that looked bad.