These cases would be prototypes of the iPhone 5 cases, based on the mockup that was provided by Apple.
There is apparently no fundamental change on the placement of the buttons and the SIM card slot.
MacRumors reports that cases with similar form factor have started showing up on the other vendor sites claiming to be iPhone 4/iPhone 5 case as seen in the image below.
It remains to be seen if iPhone 5 comes with the same form factor as iPhone 4 along with the edge to edge screen or Apple will abandon the glass back panel of the iPhone 4 and use an aluminum back panel for iPhone 5. But as we’ve seen with iPad 2, the case designs can be quite accurate. We’ve already heard several rumors that iPhone 5 will come with an edge to edge screen.
You can see the mockup images of the two possibilities below:
Mockup of iPhone 5 with edge to edge screen
Mockup of iPhone 5 with Aluminum back panel
Which one do you prefer?