I don't know if I can really consider myself an "oldschool hardcore" UT player although, of course, I have played both UT99 and 2004 incredibly extensively offline and a little online. IMO though, it's just too early to tell. The quality of it for me though personally will depend on three things at this point.
1. The base mod/mutator selection. (A nice powerful amount of these will be pretty much essential to me for UT.)
2. The general feel of the gameplay. (Can be fixed though if need be by community content or a good selection of base mutators/mods.)
3. The quality of the maps. (Although, again, this can be fixed even more easily, if required, with good community content so it's definitely the least of my desires.)