Well, no. There is no required dedicated circuit for smoke detectors in a dwelling in the '02 NEC.
I don't do houses anymore, and while I think that a seperate smoke detector circuit is good planning, most of the time it's a cost issue and we all know how that goes.
I have heard reports of this problem with AFCI's and smoke detectors from a lot of guys. I think Idaho has the right idea, for now.