Ahsanford, what do you mean by "thin mount"? Some here seem fixated on smaller FF bodies. Aren't Nikon hinting at performance and other benefits as justifying their new mount?
"Thin" doesn't sound friendly to the current direction of lens design or Big Whites...
Every time I say that, I mean a small flange distance. Sorry if I wasn't clear.
That
generally is part and parcel to a smaller overall body size, but as we all know, it doesn't have to be. All sorts of options are on the table. You could have a huge 5D grip with a skinny main body, you could have everything very thin front to back (like the original EOS M) but still a wide body (L-R from a rear view) so your hands and larger lenses can coexist, etc.
To answer your question, above and beyond what a move to a thin flange mount can do in general (well covered here at CR) Nikon can structurally improve over the F mount. In particular, their throat diameter is too small for superfast lenses and this (apparently) has always bugged either Nikon or their customers. So in the see-saw decision of thin mount vs. FF SLR mount, there is an additional finger pushing down on the thin mount side at Nikon: a thin mount is a new mount, and a new mount could logically have a larger throat diameter to support f/0.9, f/1 exotic optics. So the betting man (even before the pictures dropped) expected Nikon to 'go thin'.
Canon does not have that throat diameter monkey on its back with EF (few are clamoring for f/1 lenses it would appear), so it's more of a neutral 50-50 decision, IMHO.
- A