I think maybe the map designers for MW2 were mostly freelancers? I was never very into CS but I remember many people commenting that the maps in MW2 were made by famous CS map designers. (Which is why Karachi is a remake of an old CS map.)This is how I'm feeling too.
I have 40 days played in MW2 and I just cannot get my head around the map design in 3. Did IW's map designers fuck off to Respawn? Cos this new game doesn't feel like cod to me at all.
They had themes so you could tell who did what - some guy signed his maps with "Compound," and another guy featured the made-up "Kriegler" company a lot (like the big logo in Highrise says Kriegler). None of that in MW3...
The Cthulhu easter eggs in Lockdown are awesome though! The graffiti is some dark incantation shit and there's a poster advertising a Cthulhu bar up on that external walkway above a staircase. Anyone notice any more easter eggs?