Halo:Reach does look to be pretty cool. As far as CoDMW2 and it's online gameplay, according to most enthusiasts and Infinity Ward themselves, the game is developed primarily for online game play. The campaign is just an afterthought. I hate playing online because I'm a casual gamer, not a hardcore gamer who plays for 20 hours a day. Many of these, as I've learned, purposely find out where the Spawn point for the other team is and camps out there and waits to kill as soon as you spawn. That ups their rank and score and death counts, and that's all they care about. It's a competition to see who can have the highest score, that's all. I say take that element out of it and make it more of a mission based level, where you have to work WITH others AGAINST others in order to move on. But I guess that's not the appeal.
Me personally, I'm in it for the campaign value, and have absolutely ZERO interest in the online portion of the games. I like to progress, not to be shot down immediately by some douchbag siting in their momma's basement playing games all day and night instead of getting a damn job! LOL!