Six hours - not enough, nowhere near it. When you think back to the original CoD games and the length of campaign you got, as well as solid multiplayer, it's just damned annoying. I mean, online is online is online is online - I took a long look at my nephew playing Black Ops and it just looks the same as MW2 to me - OK, the weapons are slightly older - big whoop. It's the campaign that really differentiates a game from its predecessor.
One other thing I'd say: if these guys are no longer interested in making a decent length campaign to satisfy singleplayers, or those who want something other than what the last game offered, why do they fill the adverts full of clips from the...wait for it....
campaign? Eh?
Eh? 
Still, at least they've got rid of 'quickscoping' now, although the PC version will no doubt have that crap modded back in. I like the idea that you have to dive forwards to go prone now as well, so that should negate dropshots a bit. The one thing in these games that really takes me right out of the experience is people hopping around like Mario. You're watching a clip of an online game and people are sneaking forwards - looks realistic and exciting. Then people open fire on them, and they're bouncing around like Mexican jumping beans - it completely ruins the immersive experience.
And zombies. You can't ever go wrong with zombies.
Anyway, dedicated servers are back for the PC version now, aren't they? I might pick this one up at some point, but definitely not until it's come down in price a bit.
Edit: Yes, I know there are a few new modes - 'One in the Chamber' or whatever its called sounds like it will be fun - but I bet most players will stick to the old modes.
Not on PC you can't.
