Ok, I've been off the computer for a week or so and I'm back.
I don't think that old-school RPGs is entering its twilight. There is a revival movement by Goblinoid Games in GORE, OSRIC, Labyrinth Lords, and Mutant Future. The call them Retro-Clone games.
I think that the internet and new PDF format will continue to keep the older games alive long enough for new gamers to discover and start the cycle over again.
I played WoW for a while, but grew tired of politics and economics in a freaking game that was suppose to be my recreational time. I am sure that there are many people and gamers out there that will get disillusioned with that type and style of play in their MMORPG and their table-top RPGs.
4e Dungeons & Dragons seems to have morphed to appeal to the younger MMORPG crowds. I am sure that there will still be plenty of gamers who stick with 3.X Dungeons & Dragons because they don't like that trend in their RPGs.