The Unreal Tournament page has a pretty big update following the successful release of the latest demo. Although there have been quite a few problems with the D3D and OpenGL code, they plan on another release once they fix those issues. Here's a bit:

The new demo has been a fantastic success from a testing standpoint. We've been able to isolate all kinds of problems and find some good solutions. Yes, yes, yes we should have done this for Unreal way back when. Lesson learned. Don't forget that we do fully intend to release an updated D3D patch for Unreal itself once we get the D3D performance to a level we're totally happy with. Unreal Engine licensees all get access to Unreal Tournament Engine source code so future games based on our engine should hopefully incorporate many of the improvements we're making now, and in the coming weeks, thanks to the release of this demo.

Tim Sweeney also follows up the update with some tips for TNT users looking to get some speed increases.