Well, I really stated it poorly Vorticon. After re-reading it, before replying, I saw how it could be interpreted differently.
To begin with, I should have stated "FPS Coop campaign on the same system". There is no PC game that can do that (by nature, two PCs are required for multiplayer), and I really don't believe there is any console FPS game that allows people to play the campaign coop on the same system.
As far as HL-2 goes, it should be interesting. So long as they have an interesting story line with multiple ways to achieve an objective. I played the first HL several times through, and there was more than one way things could be done... OpFor was a pretty short and very straightforward storyline OTOH.
I don't like to say "this game is going to be better!" before I've tried it because I thought UnReal II would be great (after playing UnReal several times through, and, IMO, that was an excellent game) - but aside from eye candy it really blew.
I'll buy and play HL-2, and my friends will get Halo 2, so I'll play both in any event. Halo is really a straightforward game, but it is extremely fun when playing with a friend while drinking and kicking the AIs ass. Thats why, IMO, Halo was a great game. I played it all the way through on my own, but it just wasn't as fun as doing it coop.
-SW