After 10 years of Canon dSLRs (from D30 to Rebel Xsi) I got tired of waiting for Canon to produce a smaller/lighter system (could be mirrorless or not) and bought into a Panasonic micro 4/3 system to replace my dSLRs. I have a Canon G11 and it is a nice camera but image quality is nowhere near the Panasonic G3, it is probably just a limitation of the sensor size.
On a recent trip I used focal lengths from 7 to 175 (35mm equivalent of 14-350). It is unlikely that a fixed lens camera can offer anywhere near this range, none do yet (that I am aware of). Another lens that is in my plans is a f/1.7 or faster, no P&S offers this plus a zoom lens. Again, the G series are good cameras but can't offer the flexibility of interchangeable lens cameras.
A super G appears to be a real niche camera, appealing to a small group who want good image quality and are ok with a small zoom range and limited aperture. They will probably have to accept power zoom too. If the price is anywhere near that of a good micro 4/3 I can't see Canon selling many of these and that is why I doubt Canon will produce such a camera. I would be glad if they did though, more choices is always good!
Size and weight matter, carrying the G3 and three lenses was far less bulk than my Rebel and 2 lenses. As for myself, Canon will have to make something a lot like a micro 4/3 to get my business back, now that I have switched to Panasonic I really like it.