u4/3 is like Z-gauge model railways, compared to OO or HO gauge -- looks cute, but you pay through the nose for the miniaturization, and have less flexibility and a limited range of accessories to boot.
(I'm really hoping that Olympus, Panasonic, et al get their show in order over the next year or so and really begin to push u4/3, because in principle I agree with you -- but right now, it's not looking good.)
What I'd like to see in the meantime would be a decent telephoto-equipped compact camera with an iPhone dock built into its back in place of the display -- in effect a camera that acts as a sleeve for the iPhone, much like battery extenders such as the Mophie Juicepack. Use the iPhone's screen and user interface to control the camera, and the iPhone's storage to store the shots, but use the camera body to provide proper optics, a larger CCD, and the image processor.
Alas, developing such a gadget would not be cheap, and the vendor -- presumably a big camera manufacturer -- would be working to keep up with Apple's changing form factor.
Ergo, right now it's just promising :)
Most people don't whip out an actual camera that easily. And cameras generally aren't kept in as convenient a place (or they're always out and then they annoy all the time)