NVIDIA's GTX 470 and 480 graphics cards will be quite the heat source with some 3 billion transistors working away, but NVIDIA's reference cooling solutions designed to suit these cards are expected to keep things stable under extended load periods.
However, Inno3D already sees limited overclockability from the models with the stock coolers and even more importantly, a decent amount of noise as the fan automatically winds up some more to combat all that heat.
The folks at EXPreview have gotten hold of pictures of Inno3D's iChiLL Black Series waterblock designed specifically for Fermi cards.
Information is limited at this stage, but it sure looks compact compared to previous waterblocks we've seen Inno3D use for some of its earlier generation GeForce cards with dimensions of just 164x104x19.6mm.
However, it does sport a decent copper base which brings the weight up to 912g and I'm sure Inno3D have done enough testing in the most challenging conditions to ensure it's got some big pluses over the reference cooler.