Actually the Tokyo Auto Show one is the next GT-R (with probably a few design details probably not making it to production). It is between a prototype and production model at this stage. The concept was released a while back and was a lot more boxy looking. As for the one at Nurburgring, that was a test mule for a more aggressive G35/Skyline drivetrain but nothing confirms that it would be anything close to the new GT-R. The GT-R will not look like that. It'll be much closer to the Tokyo model.
We've had people asking if they could get on the list for one at the Nissan dealership where I work. Also, our Japanese contacts overseas did confirm that the GT-R from Tokyo is not a concept, but close to production.