I guess have still not made myself clear... I am not really worried about the bees not having enough water, at least not here in Indiana. I know that respiration produces water as a byproduct. Collecting the water in the top feeder would be just a bonus, allowing the bees to have easy access to water when it is too cold to leave the hive. (Aslo, I want the bees to continue to get their water from the top feeder year round, not from the neighbor's swimming pool.)
On the other hand, here is a beekeper from a drier climate that has done some experiments with ventilation and water: http://bwrangler.madpage.com/bee/gwin.htm
Water aside, I just don't see the point in drilling holes in my hives - allowing more HEAT to escape than is necessary - IF there is an alternative. That just seems like a waste of the bees' energy
Do the bees need ventilation? I am sure that they do.
Is it bad to allow excess moisture to drip on the bees? That makes sense.
But... if there is a way to provide good ventilation, avoid wet bees, and allow for better temperature moderation all at the same time, then that sounds like a winning combination to me.