Anybody who looks at this leaked beta and doesn't realize how old it is is just stupid. I have seen it running on a mates big PC and you can tell almost instantly that it's a very much WIP version.
It would have been good if Mark Rein had mentioned in his post just what the latest build revision is which I think would give people a better idea how old the leaked one is.
Personally.. although it's very very rough, I don't think this will hurt UT2K3 at all. This is just going to make some people all the more anxious to get the real deal demo.
/me wonders if DE will include a demo editor in the UT2K3 demo =)