Looks like a Chinese parts reseller named TVC-Mall (via Apple Bitch) has already got hold of the next-generation iPhone a.k.a iPhone 5′s home buttons and is now listing them for sale on its website. Available in black and white colors, the buttons are indeed slightly different from the rounded home buttons found in current iOS devices. While these purported iPhone 5 buttons are a bit square shaped, the center depression is still rounded, just like the present iPhone’s home button.
Quoting form the source:
The biggest surprise, or perhaps disappointment, for some is that the Home buttons appear to be round in shape. If the parts turn out to be genuine, then this would essentially quash any suggestion that Apple was redesigning the iPhone 5 with an oval touch capacitive Home button.
The same home buttons are also listed for sale in both black and white at TrueSupplier (notes MacRumors) more clearly showing that the rounded square will lie behind the front of the device and serve to hold the home button in place.