WineX can theoretically run Windows games at full frame rates - in fact NORMAL Wine runs counterstrike on my PC faster than in Windows because my OS isn't wasting so much of my resources. Zombie keeps saying "it's ok that Windows needs so much RAM, I have more than that" but the point is if I spend X dollars on new hardware, I want that X dollars to be going towards my programs, not my OS.
Calum, no offense but I disagree that it would be better to spend the time on native ports. One, game design is supposed to be very non portable - these are hardly OS's so it's just "make it run then shove it out" then repeat. So native ports wont be done until *nix systems have a signifcantly larger market share. However getting that share would be a lot easier with some more programs from Windows running on Linux. Yes, you and me both know that a Free program is usually a better one (except unfortunately for lots of games at the moment), but some people are stuck into a proprietary program, or cant adapt to a Free solution because they are stuck in their way of thinking. Wine lets Linux close that loop so that while people still use their non free programs, they at least use it on a Free base and so are moving "closer towards" the final stages of freedom. RMS puts it quite well, to paraphrase :
"having people move towards freedom is good, provided they dont accept that as the final stage." I think he was talking about using the phrase "GNU/Linux" to remind people that Freedom is the final goal given that a lot of companies now are putting non free software on "Linux" and lots of people who dont know about GNU and Free Software are accepting "just using Linux" as the final stage. Wine lets some people (even if they are "but this non free program is the best I cant stop using it!" people.) move towards the ideas of freedom, and that cant be a bad thing.
Re: UT2003, Does Mac OSX have a Linux binary compatibility feature? The BSD's do, so it shouldn't be hard to port to MacOSX with it's BSD base, and considering Linux seems to be getting a lot of new FPS games (like ut2003) it would be a cool way of each OS helping each other out.
How is Wine support for OS X anyway? If it's bad that could be a good area to focus on for some Mac development companies.