iPhone 4G: aluminum cover shown on video

By now you all have seen the iPhone 4G prototype and several photos from Gizmodo and Vietnam. Here is a new video that shows an aluminum cover of future iDevice:

As you can see the central body is different from that of iPhone 3G/3GS. We have to wait another week to know the whole truth. The iPhone 4G (iPhone HD) is expected to be announced on June 7th during Apple WWDC conference.