They milled the back panel from a solid block of aluminum which they then blasted with glass pearls to get that rough texture that is present on the iPad. Once finished they affixed a front glass panel complete with a capacitive elongated home button.
The photos of this mockup are super impressive and it’s the first 360 look we’ve been able to witness as most of the renders were only screen shot at one or two angles.
When compared, this design really trumps the iPhone 4 and makes it feel dated and clunky, with the iPhone 3GS still looking like an infant toy. Rumor has it that the feel is superior as well with an incredible (in hand) footprint.