Nvidia's new Geforce GTX 580 is going to be cooler and a bit quieter than the Geforce GTX 480, a.k.a. original Fermi. From what we have managed to find out, the new card has similar TDP to Geforce GTX 480, but its cooler is redesigned and works more efficiently than the previous one.
Don’t get carried away, as the card will be hot, with a TDP of slightly under 250W. It has to be hot, but at least it will be heavy and fancy looking.
Naturally someone will develop a water block for this card as it simply makes sense to water cool it, as you can gain some more performance when overclocking this already hot card. Of course, the water cooler will come at a hefty price, as it always costs significantly more due to the small numbers of coolers that people buy for €500 cards.
Many people don’t go along with Geforce GTX 580 name as the card should end up with Geforce GTX 490 or similar, but as you know Nvidia ups the numbers every year, sometimes even by simply renaming products. Geforce 200 became Geforce 300 without any significant change, but the Geforce 400 series have deserved its name.
Geforce 500 cards are a tweak, a real kicker so you will be able to tell the difference, especially with GTX 560 parts that should bring a lot of performance in sub $ (€)200 market.
As for the rumous that this is a paper launch, we can definitely tell you that people have cards as we speak, the big names are testing them now and they should get available on the November 9th, after the official launch.