Well not the most over hyped game of this generation but definitely up there. But, as stated, most concentrated on the internet rather than other areas which is one of the reasons sales were that explosive. But I think most of the hype came from just because it had been in the media for so long. Thus going to be talked about a lot. Most of the hype was positive of course but there were your usual detractors.
In my opinion of it all, game was overhyped and a little overrated because of it. Still a great game but claims of "best shooter" or "best online shooting experience" were kinda silly. While maybe arguable, it would not be one I'd ever argue.
But yea the hype machine for other such games such as Zelda: TP, Halo 3, Gears of War, Modern Warfare 2, Super Mario Galaxy, Metal Gear Solid 4, LittleBigPlanet, Uncharted 2, etc were all much much larger (large off the internet as well). Won't comment on overrated on those though because it doesn't' deal with the topic.