I don't see the stack overflow model as being a great fit for what facebook api developers need. The main problem I saw with facebook api was that the right way to do things kept changing, and the docs and forum didn't keep up well. You basically needed to begin facebook API work by reading the entire blog in chronological order and then keep on scanning the dev blog daily, which may work ok if you're a fulltime face…
Maybe developers should just start an unofficial Facebook Wiki.
Since people are already discussing Facebook API over at Stackoverflow, they might as well make it official.