On-Die also known as Direct-Die cooling got quite popular a couple of years ago. Watercooling addicts tried to get the best out of their selfmade cooling units and found water spilling around the CPU die itself to be competitive solution. But the obvious hurdles with leakage and complicated maintenance prevented companies from incorporating this technology.
However, I came across an interesting piece of information that reveals MSI has plans to sell special NVIDIA GeForce 8800GTX cards with an On-Die watercooling setup. Afterall it sounds quite unbelievable especially if you take a look at the second picture which shows the cooling unit at a higher resolution. But MSI clearly said so if the guys from HardTecs didn't mess with the translation. I will get in contact with them and see how they respond.
If we assume this is indeed an On-Die cooler then I would direct your attention to the last picture at the end of this post. This shows a watercooled R600 card and the pump, hoses and general appearance look very similar to the aforementioned 8800GTX board. Sadly both cards aren't available yet so the time will tell what exactly we are looking at here.