If you want to try out the multiplayer portion of
Call of Duty : Modern Warfare 2 on the PC,
Steam's hosting a free weekend starting tomorrow. You can pre-load the game in order to get a jump on the action without waiting. There's been a few of these free weekend deals with such games as
Team Fortress 2 and they always seem to be pretty successful at causing a minor spike in sales. I don't know if it will do that with
Modern Warfare 2 but free is free even if it is for a limited time.
It's just too bad I can't transfer the stats between the 360 and PC version because I wouldn't want to go through leveling up again from the beginning. I'm only doing the first Prestige on the 360 version though as I'm stopping at leveling to 70 at two times.