I don't think they will support it - but as they improve their product the side-effect is that more and more older games run in Linux.
Having said that, Unreal I rendering looks horrid ... akin to no anti-alias but in a graphical sense. It runs exactly as it is supposed to and seems to have less "story-line" bugs than the ported version.
I got the ported version of the old Unreal I - gameplay is not the best (I am not very good at difficult maps!) - natively the rendering is utterly beautiful; crystal clear and ethereal at parts. Incredible for such an "old" game.
You can't get the same quality when running under Wine at all.