This pretty much puts the nail in the coffin for CoD and opens the way for MoH/Battlefield to regain the FPS crown.
Hmm 
Maybe if next COD turns to be Rogue Warrior...
COD has an army of fanatics that play nothing except that,their gaming budget=60$ per year.
No other game can kill COD or Halo or Mario...those games can only be killed from inside and that would have to be a really bad bad bad bad game,but even then userbase will expect "return of the king"
In 2005 if you told someone that Call of Duty 4 would be more popular than Halo 3 they would've laughed at you.
Well in 2005 if you told someone that in 2010 360 will be ahead of PS3 in Europe...well,you get the picture...things change
Why COD exploded?
My theory...people where getting tired of WW2 and COD did "right place,right time,right thing"
Today the market is flooded with "modern warfare" shooters,much much harder to "lift off".
And there is one other thing...60fps,because of that COD is the shooter with fastest control response(see Stoney thread),people see(feel) that,nobody will count pixels,effects,etc...but "man,this game feels so smooth" is priceless
Not to mention the budget($200 million rumored)...