The Guardian Unlimited rolls out an interview with Mark Rein in which Unreal Tournament 3 is the main topic of discussion. A bit on the engine:
The really interesting thing is that Unreal Engine 3 performs a lot better now than it did when we shipped Gears of War, so that gives us more headroom. We're constantly improving. At GDC this year, we going to roll out some new improvements we're making to the engine - some new graphics techniques, new capabilities - most of them are still in development. But we're constantly getting better at using the technology we have.