I am more and more convinced it might have something to do with glue, or humidity, or some other variable factor.
Yesterday, when I got mine, I noticed the spots on the bottom, but it looked otherwise pretty uniform. I left it to charge.
I came back to read on it and, the more I read, the more I noticed a pinkish hue in the upper-middle of the screen. It really got annoying. Not as bad as some of the pics I have seen, but there was a different hue to the middle than to the top or bottom.
I have not used my PW today - been stuck at work. Just pulled it out of the bag now and I see no pink hue whatsoever. Trying different levels of brightness, under different lights... nothing. It's just not there.
The spots on the bottom, where the leds are, obviously persist, and I find them really annoying when reading the WSJ - but less when there is a full page of text, as in a book.
But the pink is gone for sure. Hopefully, for good.