Take a massively parallel architecture like a GPU - say, R600 - and get it to do advanced physics simulation. This is what you get...
...Arty! Still, the apparent accuracy of the simulation is impressive, although granted, we're working from a still image here. Now, how long before the games designers start modelling water sloshing around like this? And once they do, how much GPU time will be left for the graphics?
We've got a couple more impressive pics of R600 physics simulations. We'll show you them a little later in the week.