If I can add my 2 europennies...
I think that Dynon made a very wise decision in setting up a bus like DSAB so that different Dynon devices can talk to each other nicely.
Now, there are a bunch of APs out there on the market, and they have established a nice and tested product line over the years. It could be quite difficult to enter a brand-new market for Dynon with a new AP that would only work with Dynon servos, so I second Thomas' suggestion of being able to use TT of TA servos.
But, think about this. Would you not hate losing your primary Dynon unit for whatever reason, and for the fact that the AP is linked to the Dynon smarts, also lose the AP?
How about a DSAB-enabled AP head that would talk to the main Dynon box and drive the servos, and in case of loss of primary Dynon unit would still be able to fly a GPS track and to keep wings level and, ideally, also maintain an altitude? Such a device might have a knob, a couple of buttons and leds and a display, and that's it.
Another possibility would be to work with TT and/or TA and give them access to DSAB, so that their devices might be linked to the Dynons. Feeding the GPS data to different boxes is not that hard (we already do it today), and I am sure that DSAB could even be extended to enable fly-by waypoints instead of just fly-over like all NMEA APs do today.
Food for thought...
Ciao, Luca