I'm a lefty, and when I was about 11 years old, back in the mid 1960's, my father gave me his old Exacta film SLR, which was designed for leftys.
The shutter was beside the lens on the left hand side as was the film advance lever.
I loved it because I could use my left eye on the viewfinder and not have my nose pressing up against the body and could actually use my right eye to see the wider view.
I reckon that there is a market for left handed DSLR's, not only for leftys, but also to mount with a right handed version for stereo stills and movies.
Come on Canon, stop discriminating against left handed persons and bring one out!