Yes, it's very common.
I'm actually staring down a 4-year wait between trips. (2014 - WDW or bust! only about 3 1/2 years left!)
There's lots of things you can do to make things better. But mostly, I just try to be practical. The primary reason I'm not going back for 4 years is that my kids are very young. In 2014, they will be old enough to really appreciate the trip.
If I go between now and then, sure they will have fun. But I've been down that path and I'm in no hurry to do it again. Any time I think about going sooner, I reread my trip report from our last trip. That puts me off the idea pretty quickly.
Instead, I'm planning to go back in style when the kids are old enough to remember it and hopefully we won't need to wrangle any strollers. When I think about the practical benefits of waiting, it's a pretty easy decision to make.
Plus, by 2014 Disney will actually have built some new attractions. I'm hoping they will have build even more than the things that have already been announced (buy with Disney you never know).
In the meanwhile, I read books, watch shows on the Travel Channel, plan, post here, listen to park music, make recipes from WDW and basically just drive my non-WDW-loving wife crazy with my obsession.
It gets easier.