Here is an excerpt from "The Cigar Smokers FAQ." I'm not trying to change any minds, but it sounds reasonable and I figure these people know more than I do...
"Should I remove the cello wrapper for proper aging?
A good cigar will certainly age in the wrapper, just as a good wine will age in the bottle. Aging cigars, as wine involves very complex chemical processes. Oxidation, slow chemical changes, blending of essential oils are all involved. If you age a number of similar cigars, then removing the wrappers will allow different cigars to "marry", resulting in more consistence from one to another, but will not make the individual cigars any better or worse.
When aging cigars in your "daily" humidor, you're better off leaving them in their wrappers for another reason. Frequent opening and closing (exchanging the air) will result in faster evaporation/dissipation of the essential oils which give a good cigar its taste.
Many people keep a broad assortment of cigars in their humidors. With an assortment of different types, you are best off leaving the wrappers on. You don't want the spiciness from those Jamaicans mixing with the muskiness of the Hondurans. The Dominicans are mild - You don't want them to acquire any "power" from those Cubans!
Keeping the cello on also slows down the transfer of humidity. Your stored cigars remain stable - even with opening and closing the humidor frequently. You'll notice that the end of the cello is never sealed, it's just folded over. This allows the ambient humidity to slowly infiltrate the cigar. It also protects them from transfering problem like mold or bugs (shudder).
Now, if you're only keeping one or two similar brands in your humidor, you might consider unwrapping them - just so the flavors "marry". This will produce better consistency from cigar to cigar."
http://www.cigargroup.com/faq/