If it's only dampness and it's equal with both feet, ffj is right. You'll get condensation and sweat. I also wear wool wading socks to combat the moisture. I used to wear them over my regular socks, purely for warmth, but found that during any hiking, I'd sweat. The regular cotton socks would get clammy and make me cold. Wool in direct contact with the skin is the only way to combat dampness. It stays warm, even when wet. If you do manage to spring a leak in cold water, you'll be glad you had the wool.
Pad never fails to mention proper fit. I usually find myself sitting here nodding in agreement. For whatever reason, wader manufacturers decided that people with size 12 feet are 9 feet tall. I wear a size 12 shoe, and find that almost all waders are too long for my 5'11'' frame. Not only do you run the risk of leaky seams on waders that don't fit right, but I have gotten lots of rubbing when I walk. This left me soaking wet on my last trip to the salmon river. The seams on the inside of both legs were rubbing open.
I used to think that a glove-like fit didn't matter because I don't believe in buying expensive waders. I beat the crap out of them, so I get a cheaper pair (less than $90 usually) every other season or so. If I rip em, I usually only swear about thirty times. If I ripped a $200 pair, that string of obscenity would probably reach a few hundred. That said, I might be more discerning about the fit on my cheapies from now on. I've been burned too many times.