I've just added Futaba and JR high-speed digital servo support to my autopilot control board. The Futaba servos use 275 Hz refresh rate, while the JR units use a 166 Hz rate. The data pulse is the same, between 1 and 2 ms long. This is a hardware upgrade that requires the new Rev 2.4 boards.
I also wrote a page that details the Futaba PCM format. We'll have a software-only upgrade to support PCM transmitters / receivers soon.