Gearhead has a point: I was presuming you knew everything on the car is up-to-date. If you're going to the trouble to take it apart, might as well throw a new set of pads in while you're at it.
Of course, this is your opportunity to do it right: Measure the thickness of the rotors and make sure they're within spec; replace if they aren't. I'm also a big believer in bleeding the brake system once you've pushed the caliper pistons back in. I hate thinking about pushing dirty fluid back up toward the ABS pump and master cylinder.
