Generation aside, their whole execution seems flawed. Canon is great in DSLRs, unfortunately they goofed it up with M. The intent clearly was to be able to use current lineup of Canon system with new camera, the problem is the strength of that system doesn't translate well into mirrorless .
They have great lenses, but attaching the 70-200/2.8 IS to a M would be outright silly and defeating the purpose of having a mirrorless. Even my Sigma 17-50/2.8 OS which has a (relatively) modest size for a DSLR lens would be huge on my Nex, esp. with an adapter. Why spend all that money on a compact camera and an expensive adapter, just to plop lenses on it that are way too large ? And same goes to their flashes. You lose in ergonomics and features and gain very little in weight / size.
The sensor on M is the same as on their current DSLRs, which means the dynamic range and low light capability is just a tad worse than on Nex. And probably on Fuji as well.
So, unless you're a Canon shooter with a myriad of accessories, and you only plan on using the small camera occasionally, why buy into M for mirrorless ? Pretty much every other system is better. OM has better lenses, Nex has better sensor and still more "real" small lenses. Granted, there's lots of great about Canon system, but you need their DSLR to use these goodies efficiently.
They may eventually come up with enough small lenses to justify getting a Canon mirrorless, but for now I think it's a flop. SL1, on the other hand, looks promising.
Nex F3 * SEL1855 * SEL50F18 * Σ 30/2.8 & 19/2.8 * Minolta MD 70-210/4 * former Canon DSLR shooter