Is zombie campaign confirmed? I heard a rumour a few days back but didn't pay much attention as I thought it unlikely.
All in all I've preferred Treyarch's games to Infinity Ward's, in recent years - but level design on the multiplayer maps is definitely not their strong point. Most of IW's multiplayer maps are a lot better.
They don't do zombies, though, so Treyarch win - and the design on the zombie levels is usually pretty good.
I feel the need, now, to rank the zombie levels. I'll ignore the "Dead Ops" arcade game.
Worst to best, then:
Call of the Dead. The idea sounded good - get some classic horror stars to voice the heroes as they fight back waves of zombies lead by George A Romero. The inception was poor, though. Romero was just irritating (and made it impossible for your group to make a relatively safe area) and the zombies came from the ground instead of through windows - which sounds fine but didn't really work.
Five. Only one exit from the start area, annoying characters (JFK etc.), and quite a long and overly complicated route to get to the good weapons/powerups.
Shi No Numa. I probably spent less time playing this than any other zombie map. To be fair, I think it had a lot of fans - but if memory serves it came out at about the same time as some other map I loved, so this one didn't get much of a look in...
Nacht Der Untotten. First ever COD zombies map, it was fantastic fun at the time - but it was small, with only a handful of weapons and very few features you see in later maps, so doesn't stand up well now.
Verrückt. I think this was the second map, and the first that was properly thought out. Introduced loads of new features, most of which continued into every map since.
Kino Der Toten. One of two maps on the Black Ops disk (along with Five - the not so good game mentioned above) it was great to see Treyarch had brought zombies back to COD, after IW had had the reins for a year. Decent map, that I think was the first to allow you to pretty much loop around the full map - so if your timing and concentration were good you could last quite a long time by circling the full map, shooting backwards at the constant crowd following you.
Shangri-La. The map itself was fun, but this took the "Easter Eggs" side of things to a whole new level. Lots of complex steps to take, and if you got through them all (I never did) you got a tasty bonus.
Der Riese. Definitely one of the greatest zombie map to date. With a relatively simple map, but introducing teleporters and the pack a punch machine, it also had a balcony which - if the team worked well together - could be defended for hours. There would be panicky moments when you'd have to dash off to get a new weapon/perk/pack-a-punch etc. but that was part of the fun. Probably the best teamwork level (at the time - it's a bit dated now).
Moon. Nazi Zombies on the Moon?! Oh hell yes! great map, with clever easter egg side quest. The astronaut feller that followed you around (like Romero in "Call of the Dead") was annoying, but that aside this was a fantastic map.
Ascension. Fantastic fun, again. The lunar landers were great, and well positioned, the steps to unlock the pack-a-punch were clever but easy to follow, and it had a couple of decent sized open areas you could run around in a circle - with the zombies naturally ending up in the middle of (so long as you were careful) - so it was possible for several players to hang out in different areas of the map, each containing and killing lots of zombies single-handedly. Definitely the best level if your team isn't working - as you can just leave them, go somewhere else, and do fine.
Look forward to seeing Nuketown Zombies*, and whatever other zombie levels they come up with in Blops2.
*I think that's only available if you buy a premium copy of the game, but I'm sure it'll be made available as DLC too.