It's fine! GPUs run way hotter than CPUs. 60-80 is ok, although I have to say that the cooler something runs the better but it's all relative.
ATI's temps for your GPU are:
Maximum recommended ASIC case (or center of die backside for flip chip) - 105°C
Absolute maximum rated junction temperature: TJmax 125°C
Minimum ambient operating temperature 0°C
As you can see, well within specs. If you are little paranoid about the cash you just spent, invest in a high quality cooler for your card- something like Zalman or coolermaster or some other well known company.
S