Bad news for any iPhone 4 owners with attachments to their current cases; if you're planning on upgrading to the iPhone 4S this Friday, you may find that you'll need a replacement case as well.
The (presumably unbiased) folks at Android Sale put the iPhone 4S side-by-side with the iPhone 4, whereupon they noticed that the lock button and volume controls had been shifted ever so slightly in position, meaning any case with openings that let you work the buttons will be misaligned. The difference is only a matter of millimetres, which makes it all the more infuriating, to our minds.
We can't tell from the pictures if this is the SIM-less American iPhone 4S model or the standard 4S that we'll be getting over here, so possibly this problem won't apply in Blighty. But if you are upgrading this weekend and want to keep using your iPhone 4 case, take it along with you to the shop and try it out on the 4S - at least you'll know then and there if you'll be shelling out for a new case.
Source: Android Sale