I dont really play much Multiplayer, but last I checked CS was the biggest Online Multplayer, boasting somewhere around 50k players a day, I know thats not exact but enought ot make the point.
Even if Doom looks better on some level/scale, with very limited Multiplayer offerings, it will need to the one month head start.
Once HL hits shelves Multiplayer community (which as I said im not really part of)is going to EXPLODE, imo.
I dont think Valve is sitting in a corner quivering and weeping that Doom is coming out, nor do I think that of Id.
The worst criminal in human history, undeniably.
Ain't no tweetin, in jail jammies!