I'd like to see a legit magitech setting. Not Eberron, where it's the dawn of the magic-industrial revolution. I mean legitimate magical technology, we're talking ray-wands and FTL and cryonic suspension and the like. Star Trek or Star Wars, but openly Science-Fantasy instead of hiding behind a veneer of Normal Science. (And yes, I know Starfinder did this. I think D&D should pull a Paizo and steal the overall idea, but implement it in their own way.)
Also? Just write a damn gazetteer or enchiridion or whatever for the world of Nentir Vale/PoLand etc. It's a setting many aren't familiar with and which would be of interest to folks, I'm sure.
Finally, just hire Chris Perkins to put his work into official form. Iomandra is AWESOME--it's a setting of dragon pirate princes, what's not to love? I'm dead certain whatever campaign worlds he came up with would be instant classics.