Well obviously it looks like a great big iMac, but is that a bad thing? I'd say it's actually perfect for a TV. The iMac wasn't designed to look like a computer, and maybe Mr Ive didn't design it to look like a TV either but it would be a stunning looking TV.
I use my own iMac to watch everything now, I don't actually watch TV anymore. The iMac is the perfect design for watching TV with its 16:9 aspect ratio. So this concept would actually be perfect for the Apple TV.