Please be sub-4000$.
lol. Yeah, let's call it the 5.1D then. With Canon's pricing strategy, $4,500 is almost a guarantee. 6D -> 5Dm3 -> 3D -> 1DX. $4,500 fits in there nicely.
Does Canon even make a lens that can resolve 46MP?
Yep, The 100L & 135L are beast. Perhaps the New 24-70 II?
Any Canon Lens, that can take a 2x Converter with 18MP APS-C can not only resolve 46MP Full-Frame, but up to 120MP Full-Frame. Resolution-wise we're not done until reaching pixel sizes of about 0.25 micron.