46 megapixel canon Locked

It won't happen.  You may be thinking that 46MP is in the stratosphere, but it's really nothing at all, in the grand scheme of things.  You can already use a good 2X TC and can see what an inferior version of having 4x the current pixel density would be like, or use an adapter with a Nikon 1 series body or a Pentax Q, and see what center-frame would be like with hundreds of megapixels, and the fact is, some lenses just keep on giving.  The actual point of no more useful returns for FF pixel density will be about 400 - 500MP, in my estimation.  Granted, focus won't be spot on all the time, and lenses will be soft wide open, and in the corners of some lenses, and the camera will shake, but when everything is perfect, you're going to need a half gigapixel for the best lenses.

The II version would be underserved by a mere 46MP.  I've seen test shots where it was used on a 7D, with a 2x and a 1.4x TC stacked, and with just a tiny bit of sharpening, the results were sharp looking without much raised noise or artifacts.  9x the pixel density of the 7D would have been superior, as there would be no TC-related optical losses.

--
John
http://www.pbase.com/image/55384958.jpg