After playing it for a couple of days, I'll give it a thumbs up, for the main part they seem to have kept most of the good stuff. It looks good, very good in fact, and runs really smoothly.
I'll admit there are concerns, but since I'm not playing the full breadth of the game, I'll wait until it's finished before I make final judgement, but so far I'd say that UT3 is certainly on my list of 'to buy'.
UT was one of the few games that I used to play online, mainly because there was no time for anyone to start typing things like 'U N00b!!1! I pwned joo!', they'd probably die twice in that time, and UT3 keeps up that pace, so I might well look at actually venturing into some online stuff once it comes out.