It is difficult to implement a better optical viewfinder as it all boils down to optical physics where the larger cameras fit a larger pentaprism block, etc. So in order to be smaller than the 60D but still have a great viewfinder it would need to stop looking like a curvy Canon and more like old school flim SLRs where the pentaprism is very prominent from the exterior (which were arguably are of higher quality than mass produced DSLR pentamirror crap now and enabled users to manual focus due to its precision/brightness). We can all agree optical viewfinder MF is next to impossible on Rebel class, not even sure if its easy on a 60D. Pentaprisms remember being a solid chunk of glass or crystal or whatever adds substantial weight.
I am wondering what is the source for rumors of viewfinder + touch screen interaction? Perhaps I'm dreaming, but one possible revolutionary change would be to make their anniversary 650D (remember the EOS 650 film SLR was an anniversary edition), their first mirrorless. However unlike the terrible Pentax K-01 which we know is crap in CDAF performance with existing PDAF designed lenses, and basically all it is is a K-5 with the mirror thrown out, it'd be great if Canon made an on-sensor PDAF enabled system that gave us PDAF speed + CDAF accuracy and EVF as well as touch screen instant focus and shutter release. Unlike Sony designs which cover the sensor with SLT and eats light and degrade high ISO performance, how about on-sensor PDAF, no mirror, EVF, and a mix of PDAF/CDAF technology like the Nikon 1. In addition this opens up higher performance in regards to shutter lag and FPS just as SLT does on Sony or Nikon 1's electronic first curtain shutters, etc.