Das Problem soll sich von selbst lösen!
http://www.engadget.com/2010/06/24/iphone-4s-yellow-spot-issue-goes-away-with-a-bit-of-time/
Apple is using a bonding agent called Organofunctional Silane Z-6011 to bond the layers of glass. Apparently, Apple (or more likely Foxconn) is shipping these products so quickly that the evaporation process is not complete. However, after one or two days of use, especially with the screen on, will complete the evaporation process and the yellow “blotches” will disappear.
How do I know? I was involved in pitching Z-6011 to Apple.