Whether it is quiet or not is up to the fan they stick on it.
If the fan does end up to be a whiny little ***** then just decrease the fan speed. Or if you can just wait for a 3rd party cooler that is more quieter.
Im pretty sure they would have the fan at a certain speed to make sure the GPU wont get too hot so it would be a bad Idea to make it run slower. I actually have the fan in my GTX280 run a bit faster than factory speed.
AMD have gone from being the underdog to a massive thorn in Nvids side.
Nvids future is very bleak atm and they know it, look at the 295 - against the 4870X2 which is cheaper and actualy plays games BETTER what would you buy?