I have a q6600, nvidia 8800GT 512 (latest drivers), 4gigs of ram, 10mb down/2mb up connection and the game is VERY choppy.
I've turned off shadows, sound, turned down my resolution, fiddled around with firewall settings (I have no problem seeing and connection to peoples games most of the time).
So trust me, while is computer is definately crap and its time for an upgrade, even computers that meet the requirements run this game like crap.