Something like a Ricoh GR Digital IV (fixed 28mm equiv. f/1.9), but with a larger sensor would be great. But Canon will never build one because it is too niche, so we will get something with a f/3.5-f/5.6 Zoom.
I'm using a Sony NEX 5n with a 16mm f/2.8 lens, total weight is 12.0 Oz. It's a great video camera, but without a hot shoe, it's not so good for stills. To me weight is more important than size, 'cause I never carry a camera in my pant/shirt pocket.
Cameras are just tools. I own cameras from Canon, Nikon, Sony and even a 4x5 Toyo. If Canon wants some of money, all they have to do is build something I need.