4e looks like a fun game that may fix many of 3e's problems, but after 10 months of "marketing" I remain unconvinced that 4e is so much better as to justify converting three existing and very enjoyable 3.5e campaigns.
My biweekly Runelords game will probably run for another year under 3.5; my biweekly Savage Tide might convert to Pathfinder, but in any case has another year and half or more to go. The monthly game I play in (three DMs, swapping responsibilities) probably has at least 2 or 3 years left and may also go Pathfinder.
All told, these three groups represent 15 different players, none of whom are particularly interested in 4e. None of them are haters, but probably 5 or 6 know virtually nothing about the new edition. If a 4e quorum were to spontaneously arise, I'd be glad to give 4e a shot. But I don't see that happening in the near future.
If WotC ever gets its virtual tabletop off the ground, I would be tempted to run a 4e game for some good friends who have either moved far away or have kids and can't commit to regular face-to-face games. But I don't see that happening, either.
So, for the time being, I remain a happy 3e/Pathfinder guy.