Thickness-gate is a fake. That's what Apple SVP of worldwide product marketing Phil Schiller has said via Twitter. Thickness-gate is the nickname given by some over the discovery that the white iPhone 4 appears to be about 0.2mm thicker than the black one.
Ernesto Barron sent a public Tweet to Apple Senior Vice President of Product Marketing Phil Schiller about the thickness difference between the white iPhone 4 and the months-old black model. Schiller, however, chose to reply via a direct message, not a public Tweet of his own. Schiller said
“It is not thicker, don’t believe all the junk that you read.”
The fact that the white iPhone appears to be about 0.2mm thicker than the black one may seem faux to Schiller, but not just one but multiple reports have indicated that there is in fact a thickness difference, including testing a white iPhone 4 against current cases. TiPB said that some which were relatively loose on the black one fit just right on the white model, but some were so tight that it was tough to get them to fit at all.
In addition, not believe all that a person reads is one thing, but images (unless Photoshopped) are another thing entirely. Users have also reported that they can tell the difference, simply by holding a white one and a black one. Meanwhile, Apple's specs on its website indicates that both iPhones should be 9.3mm thick.
It's a small difference, but some cases are made to such close tolerances that they may either fit tightly, or may not fit at all, with a 0.2mm difference. We'd especially be concerned about cases that slide on to the iPhone 4.