A wine shop I was in recently kept all of their bottles upright rather than sideways. Not just the fast-moving inventory, but everything. Talked to the owner, and he is a guy that seems to know his stuff. His explanation was that he sees more problems with cork taint than with corks drying out, unless the wine is going to be held for a really long time (in which case, for collectibles, some producers will periodically replace the cork and "top off" the bottle), and that he'd rather reduce the risk of cork taint by not exposing the wine directly to the cork as happens when the bottle is stored on its side.
Anything to this?