The good news is that prices have the habit of dropping to the level where you can afford them. The HD 6990 can be bought for as "little" as 536 EUR now, while the "king of Vaporware", the ASUS Ares, still does 1.099 EUR. A 32-core CPU is still over the horizon, but a mobo supporting two 12-core Opterons is almost affordable, especially when fitted with two high efficiency, low-powered CPUs. This will significantly drop the amount of money needed to maintain a DC-farm, power-bill wise.