http://www.dpreview.com/previews/canon-eos-m
Having just ditched my 5D Mark-II for a beautiful and very, very capable Olympus OM-D (
http://www.dpreview.com/products/olympus/slrs/oly_em5), I can understand Canon's interest in this genre.
It's a pity that unlike the OM-D, the Canon M doesn't feature a built-in EVF, which to my thinking defines it as a strict consumer-level device. Having diopter adjustment is essential to those of us who wear reading glasses and don't want to have to use them to operate a monitor on the back when shooting - which in the M's case doesn't even tilt or swivel - so overhead or waist-level composition is impractical. Maybe they'll bring out a more serious unit up the track now that they have played a hand. It will be very cool to use your L-Series lenses though, if you already have them, and still maintain autofocus and IS. Interesting astro camera too, without a mirror to have to lock and lighter overall weight - maybe one day there'll be a Canon EOS M
a?