http://www.microsoft-watch.com/article2/0,1995,1581842,00.asp
Microsoft is expected to recommend 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.
All of those arguments about whether Linux uses more or less RAM than MS Windows just became moot, methinks.
Cheers; Leon