Nellisir
Hero
I think DnD gotten much less mainstream over the years. I'm around the same age you are and my observation is that it was a lot more mainstream when I was a kid.
I think there's some ...interpretation... about what "mainstream" means. D&D, in my experience, has much more public acceptance than it did in the '80s. I doubt it's still a staple example of satanism (I saw that film in theology class). No one blinks if I buy a D&D book in Borders. The conventions of fantasy and fantasy games are unarguably much more familiar to the "mainstream" public now than they were in 1988. Whether or not the actual numbers of D&D players have grown or shrunk, D&D has become a small part of a much larger market. In the early '80s, D&D -was- fantasy gaming. There are simply too many options for that to be true any more.
If D&D is stigmatized, I suspect it's no longer by people who don't know what it is, but by people that, 20 years ago, would have played. And D&D is old. It's not hip, anymore than He-Man is hip. And frankly, it won't be hip again until and unless something hugely transformative comes along, like Peter Jackson and the LotR movies, or the live-action Transformers movie. Personally, I think it'll be "online D&D" like we can only dream about right now*, but whether D&D will actually be "the" brand that achieves that breakthrough...I don't know. We'll see, I guess. Check back in another 10 years or so.