While I try not to ride in the rain or wet surfaces, I've found my 28c Gatorskins to be rather grippy on wet roads when I do get caught in those conditions. I wouldn't hesistate to ride my Gatorskins on wet pavement.
With that said, I would only ride them in the winter on dry days as any ice would be the end of me. If I get a winter bike this year I am looking at 38c studded tires.