Not really, the G80 cards are very powerful cards, and do chuck out heat! What are the temperatures while under load? With Rivatuner, you can change the speed of the fan while at 2D mode to about 60% which should keep it cooler, and change it to 100% while in 3D mode.
Check the temperatures that are coming out the back of the card, if they are hot, then its good, but if they are cool, then I would send the card back, as it would seem there is a problem to how the heatsink is monted and is contacting the die. Post back with load and how hot the air out the back is!