There is nothing wrong with people trying to create a mock-up of what a new device will actually look like. They are fun and sometime even pretty darn close. There are certainly some issues with the renders of the Nexus Prime that were created, but the creator sure as heck did a pretty good job of making it look beautiful.
You can see they accidentally put the image on the left upside down. Not that it is a big deal. All the blue and the potential look of the Ice Cream Sandwich main home screen sure looks nice though. Keep in mind, it is all based on rumors and little leaks from around the web. Kinda makes me want to rearrange my home screen now.
Source: Phandroid