the fact that AMD's Hemlock should show its face in late November, Danger Den has prepared a water block for it. Danger Den still calls this card HD 5870 X2.
As you can see from the picture below, the new water block cools both the GPUs as well as the bridge chip located between the GPUs. In addition to those, the new water block should be used to cool the memory and VRM parts as well. The best part of it is that Hemlock might really need it, as according to our sources with the Hemlock's 300W TDP, water cooling might certainly be the way to go.
All Danger Den needs now is AMD to release its Hemlock card. You can find the water block here