Breitbart.com posts this interesting excerpt from a promotional booklet put out by Obama's literary agent in 1991. Read it:
Being born in Kenya might make the potential readers of this book more interested in the story and perhaps that's why the literary agent wrote the bio that way. It could also be that that's what Obama told him - who knows?
Still, the point is that nobody in the mainstream media found this or reported it in 2008. It took the Breitbart folks doing the work the mainstream media didn't want to do to make the discovery. Read the entire Breitbart piece for all the context.