The somewhat infamous Stephen Walt (of, with John J. Mearsheimer, "The Israel Lobby" fame) has a blog on the Foreign Policy website. I don't have a problem with this per se. Walt is an important thinker, albeit one I disagree with rather stridently on a few choice issues (fun fact: posts like this really reduce the credibility of posts like this). And, as Matt Yglesias says, it's probably a good thing to get a few more neo-realist voices into our foreign policy discussion.
But -- always a but -- let's not get too excited. Yes, "The sort of 'realist' perspective that Walt comes from (and helps define) is definitely one that looks better in light of the past eight years worth of events." But recall why realism spent some time in the IR doghouse in the first place (not much -- it is and always has been the dominant player in international relations theory): Because it was massively, dramatically, and embarrassingly wrong in predicting the 15 years prior to that: both missing the collapse of the Soviet Union, and then not really knowing how to handle either the rise of multilateralism in the Clinton administration or the emergence of non-state actors as serious players in the international sphere (Cf.).
That isn't to say it deserves permanent exile: it remains the dominant player, and with the utter collapse of neo-conservatism and with neo-liberalism remaining on shaky territory, it has done a nice job stepping into the gap. I'm just trying to keep folks from jumping on the neo-realist bandwagon too quickly. It deserves attention -- not blind obedience (not that I think Matt is doing that, but I just wanted to give his post a little bit of historical perspective).