Whizbang Dustyboots
Gnometown Hero
You're looking at it the wrong way round. WotC is sitting on the back catalog of official D&D work that only they have the rights to sell. iTunes has shown us that, if you make getting something legally cheap and convenient enough, most people will do it.The problem is that all those people who are playing older editions are doing just fine without support from WotC. What does WotC really have to offer them?
Reprints of the rulebooks? Well, a few people would buy to replace worn copies. A few people would buy new copies out of interest. But lots? (Personally, I'd pick up the BECM "Rules Cyclopedia" and a couple of 3.5e PHB, but that's it.)
New adventures? WotC don't exactly have a good reputation for adventures, the OSR provide plenty for pre-3e editions, and Paizo would seem to have the 3.x/PF market covered.
New rules/settings? I can't imagine those having more than minor appeal.
So, really, what do WotC have to offer?
All of the pre-4E stuff WotC is sitting on is making them zero cash right now. If, on the other hand, they could produce good quality PDFs (new ones, in other words), they could turn property that makes them nothing into property that makes them money. And, the best part is, once the labor's done once, it becomes a profit center from then on.
The big concerns they'll have will be about piracy, with some arguing that it could ruin the whole enterprise, and others saying the pirates are already out there, and this would at least offer the people who want to pay a way to do it.
And as digital books grow in popularity -- and for every person who screams that they'll never use PDFs, there's a bunch more people buying all their new books in Kindle format -- that legal audience will just keep growing and growing.