PDFs. I'd like Wizards to sell D&D PDFs of the current edition again. DNDBeyond is nice, I guess. But I don't want a licensee website that stores digital books as webpages. If they lose the license, my books vanish. That's not good. I want to buy PDFs from Wizards that I can keep.
I'd also like Wizards to re-typeset the old main books (like they did with the AD&D core three) and sell those as clean PDFs instead of the okay to crap scans on Drivethru.
And while I'm at it, POD options for the original B/X books. Maybe as a single volume, and no, not the Rules Cyclopedia.