Mark Rein (Epic) made quite a lengthy post on one of the UT community forums. He talks about the recent commotion about the leaked Unreal Tournament 2003 "demo".

A leaked early test version of UT2003 is floating around the internet. It is not representative of the quality or performance of the final game. [...]

I think the closest we came to guessing (and yes, it was still just a guess) was that the demo would be out around the end of E3 or a few weeks after that. So far we're still "a few weeks after" E3 and working furiously to get the demo out as soon as possible. There are few big things we're still tinkering with such as the server browser. [...] The version of the game out there (the "leak") is missing a whole bunch of features. It has mediocre performance, lacks a ton of AI code, has unfinished levels, doesn't have Karma physics in it, has unfinished menus, lacks a ton of sound effects and music, has unbalanced, untweaked weapons, and generally is indicative of something still too early to even be called "beta". Perhaps knowing this will discourage the real fans and customers from obtaining this version and tainting their initial impressions of UT2003.