Yes, I too have the dreaded white spots on my 15" Powerbook.  I've finally decided to get the ball rolling on repairs and thought I should share my experiences with you, and perhaps the rest of you can share with us.  For those of you with the new 15" PBs, I've made a desktop picture outlining the problem available here (my apologies to the artist, I never got your name).

Are you experiencing this problem? Head over to the forums and let's share our experiences with this problem.