Idk what you guys are talking about, but my 2 year old pc, Athlon XP 1800 512mb of PC2100 with a GF2 ti 200 has lasted me just fine. I have had to replace the video card because it wont even run a few new games, Deus ex2 and Prince of Persia, but i can stil run ut2k4 at 800*600 (hosting the server with bots as well) and still get decent frame rate, now i am using my roommates radeon 8500 until I buy a new card and it runs great at 1024x768. Not bad for a PC that cost me 900 bucks to build 2 and a half years ago.
Oh and btw, UT2k4 kicks some major butt, 2k3 really was just a graphic and AI improvement over the original all the weapons were basically the same with the addition of Bombing run(which is pretty damn fun)
I havent played much Assult yet, but I have spent hours upon hours playing the same demo map of Onslaught over and over again, i really cant get enough of it. I am planning on buying this game when it comes out. I think the last time i was this addicted to a game was back in the good old Counter-Strike days, except i havent yet reached the point of breaking my keyboard yet.