The Canon pancake looks to me a lot bigger than the original Contax Zeiss 45mm f/2.8 Tessar T* MM more than 20 years back, which is a very nice lens of its time and I use it with my Contax RTSII and RTSIII a lot. Coming to 2012, my hunch is we are going to see may be a little more hubrid lens in Canon line up that can be use nicely on full frame DSLR as well as the coming mirrorless system.
Not starting a rumor here but I suspect the coming mirrorless would most certainly take the advantage of existing line up of EF lenses through an electronic adapter but almost all the lense would be too big for the mirrorless concept except this type of pancake designs. That being said, I think probably Canon can ditch the entire 1.6X sensor DSLR cameras to be mirrorless, I personally use only FF bodies because lenswise it is what makes sense for me, could consider more if the smaller sensor is mirrorless oriented.
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