I'm running on a Athlon 1700+ with 768 meg of ram and a 128 meg (9600 XT) video card and it runs ok with the "High Perfmance" setting. My frame rate drops a lot when in the cities, especially when a lot of player characters are around. However, I just fought in a 12 person raid and it didn't lag too terrible (don't get me wrong, it did lag).
I'll probably upgrade my PC if I decide to stick with EQ2.