But it's not just for huge prints, and it doesn't need a giant tripod...Well, I'm glad to see this kind of technology, but I don't need to make wall-sized enlargements, nor see the bacteria in the pores of my subject, nor do I want to haul around a 300 pound tripod to keep cameral shake so small that even 83 mp is sharp (unless Canon comes out with the IBIS to be able to use this sort of hi-res sensor). I'm an outdoor photographer and shoot mostly hand-held. I get more excited by HDR than by hi-res. Still .... I'm a sucker for new tech, and I feel that old "I want the latest" urge.
I happily shoot hand held with the 5Ds and for studio use (product work) could sometimes do with the extra resolution.
Thing is that 50->83 isn't that big a jump. I went from 1Ds->1Ds3->5Ds going 11MP to 21MP to 50MP, all much bigger jumps. Going from 50->83 is similar to the 1Ds to 1Ds2 jump, which is why I waited for the 1Ds3...
After trying the S1R multishot mode (~187MP), and recently the H6D-50 I realised that I'd sometimes like 100MP (especially if IBIS Multishot gave 400MP) and other times 'just' 50MP with a lot better DR would help
A 80MP mirrorless is of itself not enough to make me ditch the 5Ds, it's what it comes with (IBIS, Multishot DR) that will nudge me - that and a range of new RF T/S lenses.