On his blog, industrial designer Don Lehman took a closer look at the pictures of the supposed unibody design of the next iPhone. He goes into great detail about how the unibody design makes the new iPhone stronger, lighter and thinner than previous iterations.
He starts by explaining the design of the iPhone 4/4S models. On the inside of the frame were bands of metal that made up the antenna of the phone for calls, Bluetooth, Wi-Fi, GPS and everything else it could connect to. With the new design it isn’t sectioned, but rather has the sides pieces and rear shell are from a single piece of metal. Additionally the bosses screws are also apart of the single piece of metal allowing for stronger integrity, while reducing thickness and weight.
Don Lehman goes on at length about several of the details and implications the unibody design has for improving upon the antenna, increasing the integrity and several other points.