One thing that I'd really like is if they made a "D&D: Year Zero" product - either as a hardback or a boxed set.
What I mean is a setting that shares certain similarities with the Swedish RPG Mutant: Year Zero (though preferably with less bleakness). The world has been ravaged by some cataclysm or other, and people fled to some sort of long-term shelters to escape it (think the Vault from Fallout). The time has come to re-emerge and explore the world anew, and rebuild your community. You'd have some lore from the before-times, but some of it would have been corrupted through the time sheltered and other things would just be outdated.
The product would have a strong focus on hexcrawling - exploring the strange new world in which the characters find themselves. Much of it would be random, with some fixed points. There'd also be rules for the home community, both creating the starting state of it and how to improve it.