One thing I've been thinking about recently is the cultural place of RPGs. Now, being one of the new broods, I can't speak to what it was like to play these games in the 70s, 80s, or 90s. I can, based on my experience, extrapolate that these were considered kind of weird, nerdy things to do. However, even from the beginning, it was clear that RPGs had carved out some permanent location within our culture.
In spite of my age, I do feel that the's games have shifted their cultural location. In the early years it was this totally new phenomenon. Following that, it was the preferred scapegoat of those individuals who seek to explain their problems on external forces. And after that, it became one of the primary points of inspiration for computer and video RPGs, bringing a whole new group of gamers into the fold.
Even now, I feel this shifting. Shows like Futurama and The Big Bang Theory (which is terrible, and really only about "nerd" culture in this peripheral, "on the outside looking in" at a stereotype kind of way) point to reference RPGs. I hesitate to use the word acceptance, but there is at least a general, (hopefully) non-hostile way that this is a thing that people do in some form, whether it be gathering friends around a table, arranging games through message boards, Google, or Roll d20, or playing the computer interpretations of the genre.