The GTX 480's do run hot, it will start down clocking at about 100C. I have 2 and purchased the aftermarket coolers. That dropped the heat produced by 30C. Now you can't even hear them running in SLI at 100% load.
If you want, check out Arctic Cooling for the GTX 480. I swear by them and their products just work and are near silent.
Didnt realize the coolers were 80 - 100 bucks each.. I think Im allset with that!!