Also, beware of blacktopped parkinglots. They're typically much more slippery than road asphalt.

If you're being relatively safe, you really dont have a lot to worry about on wet roads, you still have plenty of traction for most conditions. As others said, maybe slow down a touch. But really...just avoid paint/manhole covers while turning or braking, and try to avoid turning and braking at the same time. Also allow a bit of extra stopping distance. And don't get crazy and lean way over in turns like a tour de france rider.