I think it is too early to tell, but a glance at the comments posted on Daniel Drezner's blog reveals that enough people are buying Mearsheimer and Walt's explicit and implicit claims that
a) America has been pursuing a foreign policy contrary to its real interests because of the powerful pro-Israel lobby, and
b) their efforts to reveal the truth will be undermined by those same forces using whatever means necessary.
I was a bit puzzled by some of those posters on Drezner's site who argued that accusing the study of being antisemitic was "ad hominem" and somehow illegitimate.
I have to commend these guys though. They could have long pulled a Chomsky or Finkelstein, as many Jewish critics of Israel like to do. I call it the Jesus-complex - naive visions of peace and justice, a refusal to go to bat for one's people, and excessive compassion for one's enemies...all this finally leads the erstwhile messiah/critic to the delusion that the Jews are going to stage another crucifixion of him/her. That's not exactly what M&W are about. They're a bit too "realist" for that.