I want a camera the size of a micro four-thirds, with a full-frame sensor. It should, of course, have as a tack-sharp 14-400mm f/1.0 kit lens that's light and easilly pocketable. Like that new "light field" technology that's been shown around, you could change the focus of the picture after you've taken it.
Its sensor should have practically no noise and such an amazing dynamic range that you could just change your iso in post production. Shooting RAW, you'd just take your picture, and it would have details in the darkest of shadows and the brightest of highlights. You would decide later what iso the picture should be at (much like you can choose your white balance after the fact).