I've had my laptop for several months. The white spots showed up within the first few weeks. They were very faint and didn't really bother me at all.
This past weekend I was going out of town, and decided to take it in for repair, since it was still covered. I dropped it off Thursday night at the Apple store. They said they would ship it out for repair the following day and that I should have it back within 7-8 business days.
I got home Tuesday. The laptop was already back. It arrived Monday. Looks great.
My only concern was that the only 'Fragile' marking was on the bottom of the box written very small in light green marker. The concierge in my building actually dropped it as he was getting it for me. It was packed very well and everything seems fine. I should think the repair company would be more careful when shipping out $3000 computers. Oh well.