Experience From - Matt Mahoney , Karl King
If you can stand to take advice from a 15-miles/week runner, I will a Suggestion:
If it's raining and the trail turns to a stream, run in the middle where the water is deepest. The water washes away the mud and the surface won't be as slippery.
My experience at Cool Canyon '95 confirmed this. For a few miles I tried dancing around to find dry footing. Eventually it became clear that if I didn't stop that nonsense I wouldn't finish the race.
Having a lot of experience at wading streams while trout fishing, I jumped into the water and went for the middle of the flow. Voila! I found the best footing and enjoyed the rest of the run immensely.
For that wet run I selected a shoe designed for High School Cross Country racing - a Reebok Harrier Racer. Very light, lug soles and vented on the side so water can drain out rapidly. I wore Wigwam Ultimax socks (design of the socks assisted by ultra runner Roy Pirrung) which have the ability to wick moisture up out of the shoe. 100 yards out of the water, the shoes and socks were mostly dry.
Despite all the water on the course, I got no blisters.