Noone is going to buy an already obsolete Mac between now and then, and noone is going to buy a rediculously overpriced PC. Last nail in the coffin, if you ask me. About time too - all the other old school and innovative computer companies went bust ages ago.
Actually, I will probably buy an Intel Mac when they come out. If the Mac runs OS X, and Windows, and Linux... and the Dell runs Windows and Linux, the extra $300 for a Mac PC is worth the cost. The only thing keeping me with Windows was that I still have some Windows software that I cannot afford to repurchase for Mac.
Basicly, anyone purchasing the "High End" computer system will buy the Mac.