Canon:
- 5Ds2, with DR that's up to scratch. Either an 8-10fps D850/A7r3 competitor or a 60-70MP high-resolution version will do. Even better if it's both. May be combined with the mirrorless camera option.
- Full-frame mirrorless. The technology has reached the tipping point and it's time for Canon and Nikon to show their hands in this field. If they don't, Sony will just grab more and more market share as mirrorless cameras begin to surpass SLRs in capability. There is a huge long-term benefit to incumbency, as Canon well knows.
- Updates to the 70-200 and supertelephotos. Preferably with mirrorless optimisation, to be equally effective with SLRs and mirrorless bodies. Much easier to have lenses that work well with both systems during the transition than having two separate, incompatible lineups.
Nikon:
- Updated UWAs and tilt-shifts. Apart from the PC-E 19, they're all pretty badly outdated. The 14-24 used to be top dog 10 years ago - now it's bottom of the pile. Again, these should have both mirrorless and SLR optimisation.
- Updated 200-400, with inbuilt TC. I believe they're already doing this (180-400mm).
- Full-frame mirrorless bodies. Same reason as for Canon.
Sony:
- A9r/A9s. One fast, one medium and one slow in the A9 series, all with top-tier AF. This might need a bit of redistribution of names - A9s for the current A9 (fast and low-resolution), A9 for something in the 42-50MP, 10fps range (like the A7r3) and A9r for a slow, ultra-high-resolution, low-ISO-focused (perhaps even Foveon-type multilayer sensor) body.
- A better 70-200mm f/2.8
- 200-400mm f/4 with inbuilt TC. Or even a top-tier 200-600mm f/4-5.6 (they amount to much the same thing).
- 500mm f/4L
- An end to the Sony lens price premium
Sigma:
- Tilt-shift lenses
- Sony FE-mount lenses
- Updated long telephotos
HP:
- An update to the Z3200, or at least some other indication of long-term support for the photographic printing market and the Vivera inkset.
EFI/Agfa/Roland/others:
- A UV-curable flatbed printee aimed at the art and photography markets - more printheads for more inks, and a more reasonable size (say, 44x96", for large panoramas, or a smaller 24x36" model) rather than room-sized
Piezography:
- Inksets compatible with Canon/HP thermal inkjet heads, not just the high-maintenance Epson piezo heads
- An updated true neutral inkset using a lightfast blue toner to cool the carbon black, not the current fading ones.