If you want to look business casual these waterproof Rockport oxfords are pretty low-key. They look good for at least a year. (After that they make you look like a guy who isn't too hung up on how he looks.) They obviously don't cut it during drenchers but they're ok for lighter rain or shorter commutes.
Ivan said:Hey, had the same problem 2 winters ago and stumbled across BOGS or BOGGS made for fishing and stuff they breath well and are super tough.
I have a pair of BOGS as well. They are great. A little funny looking, but who cares if they keep your feet dry and warm. http://www.backyardstyle.com/shop/index.php?page=shop-flypage-20422
I wear these in the fall (or Neos) and change over into my winter hiking boots for temps below 30 degree down to temps of -40.