Ok, three graphic card will cost consumers a lot of money. NO point to buy a motherboard like that, unless you're a hard core gamer. who don't care about the cost and only care about the performance.

You don't buy three at once. You buy one or two, then when you upgrade you keep one old one behind for your physics/GPGPU work.

But when you want to upgrade, there'll be a new better product comes out.
direct x 10 will be the main feature for next gen graphic card. So waiti for a rd600 motherboard and R600 graphic card maybe more sensible.
R580 or + will only feature 64bit HDR, which i think R600 will feature 128 bit HDR or even higher.
Only about 2 months waiting for a next ati's next gen graphic card.