Canon should find ways to get FAST AF (like Nikon V1 ) build an APS-C sensor compact mirrorless with just 2 or 3 small basic lenses and a EF/EF-S adapter. This will get Canon on the map of mirrorless.
They could but its a very crowded market where as like I said I see larger sensor fixed lens mirrorless as a fertile and as yet largely untapped market.
Personally I'm supprized it took so long for any of the big guns to move beyond the typical 1/1.7″ sensor thats been in high end compacts/bridges for years considering how intense conmpetision has been. Not only does it potentially offer what I believe the majority of users are after in a smaller/cheaper package but ties the manifacturer down far less than an interchangeble lens system does.