If you are talking about this: http://www.apple.com/iphone/#video http://www.apple.com/iphone/#video (05'40") then I understand they are picking the best plasti

If you are talking about this: http://www.apple.com/iphone/#video http://www.apple.com/iphone/#video (05'40") then I understand they are picking the best plastic inlays to fit one particular chassis (as the video also shows). But that is unrelated to the outer edge CNC milling. What I believe has happened there is that the CNC tool adjusts its path to compensate for mounting misalignments by using a feeler. If the feeler is worn out or there's any other issue then the tool may re-adjust wrongly. I'm speculating, but I'm starting to believe it's not a design change; just a little f-up.