This follows on a post by Alaya Dawn Johnson in March about how the recent paperback edition of her book Racing the Dark is being marketed to that section in Borders bookstores instead of the SF/Fantasy section.
It brings to mind a 2006 NY Times article by Nick Chiles, Their Eyes Were Reading Smut that I came across last year when I was processing my own horror about what composed the African American section (which I went to partly because I was participating in the 50 Books POC reading project and was seeking literature by African American writers). Basically, as Nora goes into in her post, those sections tend to be largely really trashy romance novels, incongruously set side-by-side with some of the best literature in the world. Including some top-notch SF that should really be shelved with the _rest_ of the science fiction and fantasy.
I would like to encourage fellow SF fans to visit African-American lit sections in your libraries and bookstores, and then to share comments with those places about the preferences of these authors (and you, if you concur) for where their books should be shelved.
While you're at it, you might consider picking up Their Eyes Were Watching God, by Zora Neale Hurston, after which Chiles took the title of his article. I read it last year and thought it was amazing. (And for those of you put off by such things, don't worry, it's mostly not about God. It is about very real-seeming people, and it's wonderfully written.) It will likely be in that section, and it makes more sense to put it there, since it is very much about the African-American experience.
Fantasy and science fiction set in completely different worlds or futures that happen to be by black authors or have dark-skinned characters on their covers? I agree with Nora - they should be shelved with the rest of the books in the genre.