KTM are due to roll out the new bike for 2014 which means they may not quite have the upper hand they they currently enjoy. I recall quite a few gearbox issues when the 690RR was debuted.
On the other hand, the HRC bike will be more than a year into development with several rallies under its belt. I don't see Despres going anything less than a full factory ride so in that, KTM and Honda are really the only viable options as it is right now. Yamaha, while a good bike, is a regional effort from Yamaha Europe or France depending on the team.
I suppose four wheels is an option, but for the record, I have only heard that rumor here and once on twitter. Look at the cars field, there is Mini with no challengers. A move to a buggy, quite frankly, would be a step backwards for a 5 time winner, even if making the jump for the first time and again, I would be surprised to see Despres step into anything other than a full factory effort whether it be 2 or 4 wheels.
Now if the old Citroen rumor becomes more prevalent, perhaps they could field a superteam of Seb Loeb and Cyril. An all French effort would be quite the news making event and a full Citroen factory push may be enough to entice Cyril to the dark side of 4 wheels. Short of that, I expect him to stay in bikes for another 2 to 3 years before making the switch, perhaps when Peterhansel makes the jump to trucks, that may be a good time to fill his seat at Mini. I just don't see the cars as being very competitive in the current state.