If you hop over to canonrumors there's a bit of stuff flying around about a mini-sized DSLR. If the assorted bits of info available so far are correct, it would be SMALLER than the mirrorless GH3, while retaining the native use of DSLR lenses. Of course, the mirrorless system may still have an overall size advantage if lenses are considered, and there are other smaller bodies to choose from also.
This does stem back to an interesting comment made by Canon even before the M was launched. They said that if small cameras were the goal, mirrorless wasn't necessarily a requirement. Since the M did appear I guess this comment was forgotten until now.
I guess the side question is, how useful is a smaller body without small lenses to go with it? Will there be more pancakes to come?
Summary of rumoured stats so far include:
18MP APS-C sensor (again!)
Kit zoom bundle US$799
3" touch screen
Sounds pretty much like a 650D but smaller. Presence of OVF would negate speculation Canon may be going Sony SLT style.
No mention of AF but I'd hope it would at least be comparable to a 650D level product.
There's invites gone out for something happening this Friday so we should find out then if these rumours are right.
_________________Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.