I wonder - will Canon give us similar lenses with EF or EF-S mount? Or, is there any physical possibility someone will hack together an adapter mount to retrofit EF-M on EF-S APS-C cameras?
Well, that adapter would either have to
a. Physically put the lens inside the camera body, and in the case of the 22mm lens, probably put a decent portion actually inside the traditional EF mount. It has to make up for 10+mm of flange distance...not an easy task
b. Use glass to distort the image from the lens to match the EF style. So, now you're talking an adapter that is either really expensive (think $3-400+), which negates the point of using those lenses (you can get a legacy 28mm f/1.8 cheaper). Or, you're talking a $30 adapter that ruins your image quality because they use crappy glass
So, I wouldn't expect an EF-M to EF adapter. More likely, you'll see people realize that EF-M means they can potentially use the same legacy glass that Sony E-mount cameras can, which means there is a lot of older, cheap but great lenses they can have instead