I came across this article from the LA Times where the guy who is the author for the Stuff White People Like blog gives his reasons for doing it. Here's a snippet from the story:
By "white people," Lander doesn't actually mean the more than 221 million Americans who check that box on the decennial census. But that's part of the fun. Lander is doing to whites what scores of journalists and politicians do to non-white minorities every day, "essentializing" complex identities -- that is, stripping away all variety and reducing them to their presumed authentic essences.
One irony-deficient reader complained that the blog was less about white people than it was about yuppies. And without knowing it, she was cutting to the heart of the joke. Lander is gently making fun of the many progressive, educated, upper-middle-class whites who think they are beyond ethnicity or collectively shared tastes, styles or outlook. He's essentially reminding them that they too are part of a group.
So, yes, it's intentionally racist. But it's also meant to be satire. And based on all the comments and visits he's getting on his web site, I would say he is achieving his goal. He's gotten a lot of people to think and talk about the issues of racial stereotypes.