I have this problem something fierce. Back in high school, I was nicknamed "the campaign reaper," because every campaign I joined wound down or petered out as their players worked their way into my games. It actually made some of the other DMs pretty upset...
Since 4E came out, I've gotten to play exactly five sessions. I truly enjoy the occasions in which I get to play. For me, it's more about not having to be in an "authority position." I'm usually in positions of some responsibility at work, so I don't enjoy being constantly relegated to putting the game together, getting the players together, and determining the narrative. Nevertheless, I'm usually the only one in my circle of friends with the motivation to get a game together and make it happen.
Most of the games I know of going on around here are 3.5 or Pathfinder games. I'd love to play 'em, but I've kinda burned some bridges a year ago when I didn't reject 4E wholesale. The 4E crowd that I know of are almost entirely players.
But it's not all sour pickles. I've been Jonesing for a Vampire game something fierce the past few years, and I'm able to get virtually all my 4E players to go along with it. One of the great things about being "the only DM" is that you get to decide what's played. When the options are to either play what you run or play nothing, it's comparatively easy to find players for your game.