Mine also not on the poll. With the level or errata & tweaks (a GOOD thing, IMHO, especially the tweaks), I've stayed away from paper products for a while. That said, I subscribe to DDI and am fairly happy with it now (though it took a while) and I still buy the occasional thing like dungeon tiles or fluff-heavy books.
Last mechanics-heavy rulebook I bought in print was Heroes of the Fallen Lands to see the Essentials material native instead of DDI.
If the books came out in electronic format that would keep up with errata added I definitely would have purchased them, there's some great fluff out there. Of course, that assume that I could use them on both my computer and my tablet without repurchasing.
This isn't a slam on the errata, quite the opposite -- I think we have a better system for it. And if it's software we've updated both patch levels (errata = bug fixes) and minor version numbers (large scale tweaks + rule subsystem changes like mounted combat, flying, save debuffs, etc.) Rather, it's saying that my 4e purchases have been mostly electronic, and since that's subscription based rather than product based 5e hasn't changed anything.
I do know that going 3.0 to 3.5, and 3.5 to 4e, my purchased dried up. Makes it hard for WotC - announce a new edition early enough to have real playtest feedback that can change design (instead of just development) parameters, and that same lead time shoots yourself harder in the foot for sales of the current generation of the product.
I know in the industry the time before a new product is expected they start discounting the current generation in order to keep an income stream and lower inventory levels, perhaps Wizards can see if that lesson also applies for D&D material. It'll sure go on sale AFTER the next edition comes out.