Apparently, some people in Portland, Oregon, like the idea of wool jerseys (see the FAQ page): http://www.portlandcyclewear.com/woolcyclingjersey.html

Yellow Jersey, in Wisconsin (http://www.yellowjersey.org/wool.html), offers wool jerseys by Kucharik and says this: "Modern 'Superwash' wool is knit in such a way that it is not only super soft against the skin, with all of natural wool's wonderful attributes, but you can machine wash and tumble dry cool. That's correct--machine wash!"