What are they waiting for? I DO NOT wish to mount my EF 24-70 or 70-200 on that tiny thing - what's is the point buying mirrorless
The point of small/light weight mirrorless cameras is that they are small and leight weight. Always use the right tool for the job. The EOS-M is not the right tool for big/bulky/heavy zoomz, but it could be the right tool for small/non-bulky/light weight primes.
I've been using my M with the 22mm lens and a 60mm EF-S macro with the adapter until Canon releases another prime in that range. The 60mm is about the limit of what I'd want to put on the M in terms of size and weight (basically about 12 ounces and 3" long without the EF adapter). I've messed around with the M using a 24-105 and a 70-200mm, even a 300mm/4, but if you want to shoot lenses that size with it, you need a VF... something to put up to your face so you can balance a lens of that size. And if that's the case, IMO you are better off with a Rebel.
I hope Canon will release a decent compliment of EF-M lenses with useful focal lengths. Don't need a 300 or 400 mm, but a few primes (maybe, a 15mm, 30mm, and 60mm to go with the 22mm) and a couple of zooms (a 15-60mm/4 IS, a 45-200mm/4~5.6 IS) would be nice and what I think they'd need to offer in order to compete with the 4/3 lens selection.