Maybe an old Dream is coming true the Canon B4 ENG-DSLR.
link
But there is an issue the image circle of B4 lenses is to small for the big EOS ASPC Sensors watch video below.
With ML Raw Zoom mode it´s possible to record a small part of the 4752x3168 sensor 1920x1080 a 3x Crop on the 50D.
I did a little research and it´s working in theory (image below) . Can´t wait to try it..