The dash should be waterproof enough to park in the rain once in a while, it wouldn't hurt to cover it though. For short periods, park into the wind, and leave the windshield in the down position, which will help.
Worry about the brakes, as the pistons can become sticky if wet often. At the end of the ride, hit the brakes hard then wobble the bike, this will exercise the pistons by allowing maximum motion. Do this often if you detect dragging brakes. You might also find the parking brake, center stand, and side stand getting sticky in wet weather.