There is a decent sized interview with Nathan Stewart about D&D over at Forbes, but this is the quote that really caught my eye:
Q - One of the big goals of fifth edition was to revitalize the brand overall –to make Dungeons & Dragons associated with stuff like video games, board games, books, and comics as much as it is with tabletop RPGs. Is the brand where you wanted it to be at this point?
A - Is it where we wanted it to be? Let me back up a little bit and say that for the first part of your question, we obviously had big goals for the in shoring up the core of the brand –the tabletop RPG fifth edition and the playtest, that was the heavy lifting done behind the scenes. Wizards is publishing the spiritual core of the brand.
But yeah, on the whole, Dungeons and Dragons stopped being a tabletop game years or decades ago. I mean, we’ve been a powerhouse in video games, for years now, and we’ve had movies –whether you like them or not, we still had them– tons of novels, comics, apparel, table top minies, just a lot of stuff across the board. So I will say that in terms of the 40th anniversary, I thought it was a tremendous year to celebrate all things D&D. We saw people coming back in waves, we’re seeing tastemakers and celebrities continue to devote their love of D&D publicly, and I think that’s a sign that culturally, you’re hitting the marks that you want.D&D stopped being a tabletop game decades ago? That would mean at least back to 1995.
Dungeons & Dragons was a viable tabletop game in the 3x era. 4e is where it dropped much of it's tabletop luster, and that was in 2008.
Still, if there were any doubt that those migrating to D&D 5e are already playing a dead system...