I don't think that there is really enough solid data to get an accurate picture to say if the game is bigger now or even as big as it ever has been, at least as far as a whole goes, but my opinion is that is bigger only because it has more exposure. I saw the reference to the 80's cartoon and national attention, and well that just brings to mind all of the current D&D themed pieces of media. In the 90's with PC's coming to every home you had several PC games based on the games rules, or at least as close as could be. The players of those games may not have been PnP players at all, they just liked the video game. You also had the Baldurs Gate Series and Neverwinter Night games, and I know friends that loved those games but never played the PnP games. With 3rd edition you had two new PC games almost right out of the gate and a couple of games for consoles, you had two live action movies, as well as an MMORPG with the 3.5 rules. While I am sure many a D&D PnP gamer takes part of these other bits of media, I am sure the other is true as well, and those people who don't play PnP games, but like video games probably play the D&D titles.
So to say is D&D as big as it ever was, I really think it depends on how you are measuring it. If you are talking strictly on a PnP basis, you could probably measure it in product sales data and get a close idea. D&D in general, that is the franchise as a whole, I would have to say is bigger now than it was back then as far as exposure and those people who enjoy the game, either on paper or on their game station of preference, or for those like me, both.