Full Frame: ...and a mirrrorless FF (we'll see).
A mirrorless entry is no mirrorless FF. I believe we will see a competitor of the Nikon 1 and like the Nikon, it will have a new bayonet mount.
My guess too. A FF mirrorless would be too user friendly: you could use all your old lenses, evan the very old FD ones and it would be a direct competitor to the DSLRs. Canon doesn't want you to love your camera unless you have payed $10k for it ;-)
Ok, I've just found one "pro FF mirrorless" argument: It's the only gap in the lineup of the competitors (the M9 is too expensive and exotic for most people) and therefore the only chance for canon for some strong sells.