Mark Rein from Epic Games said last week that don't have any plans yet to make a new single-player Unreal game:
Eurogamer: Talking of Unreal, it's, what, more than five years since Unreal 2. Are you ever going to make a follow-up to that? Is there any possibility?
Mark Rein: I'm sure that at some point in our future we will make another Unreal, single-player, story-driven game. I'm sure at some point there will be one. There are no plans to do one today.
Eurogamer: Why haven't you chosen to do a follow-up to Unreal 2 to date?
Mark Rein: I think we've been really happy with the multiplayer-oriented Unreal Tournament. Despite what people feel, people get this crazy idea that if you don't sell five million units it isn't a success, but we heard today that we've shipped over 1.2 million units of UT3, not even including the Xbox 360 yet. We make good money on Unreal Tournament, and it's a good game that we love to make, and it's not a five-year-long production and it's a great test-bed for lots of cool things that we want to do. We like making this type of game, and we have Gears of War as our kind of vanguard, single-player graphic showcase type of game.