Getting an allignment will not fix it necessarily, but if you take it to Ford that's what they'll do. Your tires are covered by Ford only up to 12K (although some have had some success getting Ford to honor beyond this), after that it's Goodyear's problem and they blame Ford. Good luck. I haven't seen a TSB for it and even so it probably just says to do an allignment.
Also, rotating the tires will not fix cupping. Cupping is perminent. Rotating the tires will only hide it for a little while until the new tire in that locations cups. Most of us have had success with just replacing the Goodyear tires. Others claim you need new tires/shocks/axle/etc.
Personally, I dumped the goodyears and replaced with BFG's and haven't had a problem in over 30,000 miles. My Goodyears were affected by cupping at 4500 miles and ruined by 16,000 miles (which was too late to force replacements by Ford).