As I've been predicting, this is the start of the merging of the top end of the PowerShot series and the Rebel series. It's the latest Rebel in a PowerShot body, basically.
This camera isn't for me, but I don't have any Rebels nor PowerShot cameras, and I don't have any interest in such. However, many moons ago when I bought the original Digital Rebel as an upgrade from an Olympus superzoom P&S (my first camera), the EOS-M would have been very tempting, indeed. You get the latest-and-greatest APS-C sensor in a minuscule body and an entry-level price, plus you can mount almost any lens ever made.
I'm curious, though: what's the Shorty McForty look like mounted to this thing with the adapter? I'm guessing it won't be anywhere near as much of a pancake at that point.
Then again, I don't think 40mm is an exciting focal length on APS-C. Personally, were I to buy this camera, I doubt I'd ever take off the 22mm pancake...but, once more, I've already got a 5DIII with the ShortyMcForty body cap, so why would I want an EOS-M?