Now why did ATI release the X600 now when PCI-Express for notebooks won't be out until next year?
basically because it has long been a part of GPU manufactures marketing policy to announce products LONG before they are available for purchase. This is always the case. They hope that by announcing the product earlier, they can get a bigger PR boost and more media time. basically, that announcement was meant for investors and such, not really for consumers.
I have seen from some manufacturers that they are expecting to release PCIX notebooks by the end of the year...but then again, those same manufacturers have a long history of not being right about the time they expect their products to get to market either.