Nashbar has a carbon cyclocross fork with disc brake mounts. Suitable only for frames dedicated to long axle-to-crown-race distance (mostly cyclocross, potentially touring).

Works nicely with Avid BB7, also can be used with long-reach dual pivots calipers (and Kool-Stop salmon pads), both have worked well on the same loaded bike. I have yet to prove any advantage to the disc brake.