COD Modern Warfare 2 Free Multiplayer on Steam

If you haven't played Modern Warfare 2 online multiplayer yet, this weekend is your lucky day. Steam is offering a 3 day pass to online multiplayer this weekend starting sometime today (April 8th).The game will be free to play presumably until sometime on Sunday evening; there isn't a specified starting or ending time. Check the Store section of steam for the pre-load link and start downloading.
I finally get to try out some Modern Warfare 2 multiplayer; I'm still not happy about the lack of dedicated servers but at least I can try it for free. I played the single player on the console at the local game center, but I was unimpressed with much of it: Why helllooo red jam smeared all over the screen.. why couldn't that have gone the route of L4D2 blood smears?
I'm going to give multiplayer a solid try, but I'm not expecting it to change my mind on purchasing Modern Warfare 2. Plus, I'm probably going to get rocked by all the people with their weapons unlocked.