Bob,
I'm not trying to talk for Yamaha here and I for one would love to see a 6 pedal type Ketron pedal be available for the Yamaha, but, in all fairness the MFC10 is a breed apart from the Ketron pedals. First of all, you can program up to 9 banks of pedal options on the yamaha (yes, I can also program 10 banks in the Ketron products as well) but I also have an expression pedal built in (Ketron charges about $50.00 for their volume pedal) and, if I need more expression pedals or additional pedals, I can plug several more individual Yamaha sustain and expression pedals into the back. This could be vary valuable to those needing more controllers. Also, their are lights on the foot controller so you can see what you are doing easily on a dark floor. So, I still think you get a lot of options available with the MFC10 which you don't get with the Ketron 6 or 13 pedal.
George Kaye
Kaye's Music Scene
Reseda, California