52% of the popular vote is a landslide?
Look at the county electoral maps in that link I posted. He did almost exactly the same as Kerry. The only real difference was that McCain didn't do as well as Bush.
A landslide is something along the lines of Reagan or FDR's electoral maps, where the average person looks at it and immediately says "Wow, that's a lot of red!" or "Wow, that's a lot of blue!" Obama's electoral map is Kerry's losing map plus a handful of swing states. The average person looks at it and says "Yeah, that's generally how it looks, only with a bit more blue places than normal." From a campaign that was claiming it would get 400 EVs, it's actually pretty disappointing, especially considering how much money he spent to get there. The fact that he got the triforce of Ohio, Pennsylvania, and Florida (all by very narrow margins, incidentally) does not make it a landslide. If he hadn't gotten at least two of them, he would have lost.