Would you carry a bi-lens camera or two cameras?

The biggest complaints about superzooms seem to be poor image quality (softness, CA etc), slow speed and poor low-light capability relative to SLRs. Many of the problems could be improved if we were willing to sacrifice large zoom range like 35x.

Bi-Lens Camera

One option might be to have two lenses, say 20-150 mm and 150-1000 mm effective focal lengths, mounted simultaneously on one camera, so that you just twist them to swap lenses. Has such a thing already been tried?

Two Cameras

Another option would be to carry two cameras. There are already several good cameras with 20-150 mm or something similar. If Canon were to come out with a 150 - 1000 mm camera, would you be willing to lug around two cameras?

I think that I would be interested in either of these options. If a lot of others feel the same way, it would be a great marketing opportunity for Canon.