With each new CoD that comes out each and every year, do you fans of the series immediately look at the previous "omg best game ever" CoD from the current year (in this case MW3) and just... replace it with the new one without looking back?
I almost imagine CoD fans buying the new game, labeling it GoTY, turning to the previous year's game, and taking a hammer to it because "it's not THIS year's game, so it SUCKS!" --- Now Let's Playing Mega Man Legends 2 and Tales of Graces f - http://tinyurl.com/bo7nxnx
I'd only play 4 or WaW if people were on / it wasn't hacked to pieces. MW3 was about in the middle of the recent years' CoDs. Certainly not the best, but not terrible.
EDIT: I think Black Ops II is going to have a lot more hype surrounding it because they're changing the era once again. CoD4 completely changed the series because of its jump forward in time. Once again the CoD series is doing that, which opens up far more possibilities than they can work with in the modern setting. Gameplay will be the fun, familiar fast-paced shooter it is now, but the potential changes which we'll find out about in the coming months might make Black Ops II worthy of replacing a previous CoD as one of the best.