Microsoft recommends that the "average" Longhorn PC feature a dual-core CPU running at 4 to 6GHz; a minimum of 2 gigs of RAM; up to a terabyte of storage; a 1 Gbit, built-in, Ethernet-wired port and an 802.11g wireless link; and a graphics processor that runs three times faster than those on the market today.
OS X sales figures shoot through the roof...
Honestly, do you expect HD's to increase tenfold from about 100 GB to 1 TB in two years? AND THAT'S JUST TO HOLD THE OS!!!!!!