I believe the GPS track detection speed limiter unlocking will be disabled for GT-Rs coming to North America (for anyone else who is reading this, the GT-Rs in Japan are speed limited to 111 MPH unless the car's GPS detects it is at certain registered racetracks, whereupon it unlocks)
More bad news for modders, the car is very particular about air flows, fuel flows, temperatures, emissions, etc. You can't use out-of-spec parts (power flows, etc) without tripping an engine code. Hey, the car IS an Ultra Low Emissions Vehicle, which is pretty surprising for a 480hp car, i guess they're trying to keep them that way. Not sure why after-market rims would trigger a code, probably a safety thing?
ECU programming is tightly controlled too, only 'real' tuning companies like HKS, Mines, Top Secret, etc will have the electronic keys to unlock the ECU and make changes.
On one hand, this sort of lockdown protects the user from wrecking his car and also protects Nissan from having to deal with crazy warranty issues arising from people making unauthorized mods. However, it's gonna be a real wet blanket on enthusiasts because one of the reasons the original GTR was so popular was because anyone could fairly easily make changes.
Who knows, maybe those keys will get leaked some time in the future?
But let's be clear, even in completely 'stock' form, this thing should haul some serious butt!