Newsweek thinks so. In a recent article about nerdcore hip hop, Brian Braiker writes:

Of course, ever since Vanilla Ice's 1991 flameout, the rare white rapper has been derided, forced underground—or both—with the exceptions of Eminem and the Beastie Boys. But all of a sudden white rappers are enjoying a mainstream renaissance: VH1 has a hit on its hands with "The (White) Rapper Show," an "American Idol" for would-be Eminems, and in February Bloomsbury will publish "Other People's Property: A Shadow History of Hip-Hop in White America," by Jason Tanz, an editor at Fortune Small Business. There are two indie documentaries about nerdcore in production, and their online trailers have each netted more than a half-million views. The concept of being a white rapper is no longer a joke.

I don't know that one reality show, one book and two unfinished documentaries make a "moment," but I have noticed quite a lot of talk lately in the blogosphere about white people's relationship to hip hop, most of it inspired by Tanz's book.