I think its worth a try. I'm assuming your card is good for the medium settings (I run medium with my 8800GTS 320), but I was worried about the RAM. 2gig for XP sounds about right. The game is supposed to take advantage of dual and quad-core procs, so you might miss a little performance over having a single, but that might be minor. If you get it downloaded, one of us in H Company will make sure you get a buddy key. I think we get them online via our account page...
Keep in mind that EVERYONE who plays this game gets a sudden shock along the lines of "WTF? I thought my system was good!?!?" Don't worry, its normal. Take a look at the textures and architecture for a bit, and you'll see why its such a power-hog.
Feel free to use H Company's forums too.