I'm sure that more than 1 NEX has been sold on the basis of it being able to use Leica M glass (hey, if you blow your cash on an M lens you don't have much left for a camera. Or your old M5 finally died and you can't afford an exorbitant amount for an M9 to replace it).
Still, i'm presuming the EOS-M "not being able to shoot without a lens" is just a temporary thing. My EOS 3 doesn't like shooting without a lens either, but a $20 AF-Chip fixed that right up. And seeing as the EOS-M can take regular EF lenses with an adapter, there's your fix: Just put on a regular EF-chip and then the camera will think it's just shooting an EF lens on adapter, no matter if it's really EF, FD, A, M, L39, M42, whatever.
And if that doesn't work, I'll give China 6 months and there'll be an AF chip for the EOS M anyway...