I've just made up a batch of preserved lemons following very similar recipes in Wolfert's _Couscous and other Good Food from Morocco_ and Walden's _North African Cooking_. Both of these recipes say there is no need to refrigerate your jar of lemons; it can be kept up to a year out of the fridge. Wolfert even says you can re-use the pickling juice.
Now I'm browsing for recipes to use my preserved lemons. I happened to look at the recipe for making the lemons in _The Essential New York Times Cookbook_ (love this book!), and see that this version is more or less the same as what I did (only the spices differ a bit), but it recommends keeping on a few months, and those in the fridge.
Why the difference? I'm thinking Wolfert would be more of an authority here.