I'd say that your cards are running a little hot but by no means are they bad. Since they are in a SLi configuration you must make sure you have good airflow cause you now have twice the heat to deal with. Airflow is key to keeping temps lower.
As far as how hot they run well just check out a X1900XTX and compare, they easily run intos the 80s and even touch the 90s, those would be the hottest cards on the market. Even the X1950XTX isnt much better, nvidia's last 2 generations of graphic cards run cooler since there was less power draw than X1950XTXs, while the 8800GTX/S experienced a mild increase in temperature from the 7 series they still are 75% of the time will run cooler than a X1950XTX.
Your cards are fine but they are running a little warm for typical nvidia graphic cards which would be expected since your running them in SLi. Make sure you have good airflow and see if that helps at all..