A late night post by Mark Rein to the GT boards gives a pretty good list of all of the improvements made from Unreal to Unreal Tournament for the curious. On top of that Mark has word that one of their contract workers who did the "fire engine" as well as many CPU optimizations for Unreal has made his way state side to work for Epic in house. Here are some of the planned improvements still to come:

For most of the past year he has been working on an incredibly powerful new animation system that will be integrated into to the Unreal Tournament Engine after UT goes final in a few weeks. In addition we're planning on a new particle system, some AI infrastructure improvements and hardware transform & lighting support. These things won't ship in the box (too close to finished to add major new features) with Unreal Tournament but are geared toward other projects we'll be working on after UT ships, including Unreal2. Tim has also been rewriting the editor in his spare time and that, along with an exciting new next-generation renderer, will take priority once UT ships.