2009 GT-R Modifications

There's been a lot of articles surrounding Nissan's attempt to limit modifications to the new car and how the GPS system tracks whether you're on a race track and void warranties and stuff.
This article
from Motor Trend gives some detail on what has been done by the famous tuner MINE's and some of the restrictions Nissan has put on the car. Now keep in mind that the US spec car might or might not have these restrictions.