I, Cringely: What Lies Beneath: Why Microsoft Should Build Its Next Version of Windows on Top of Linux "Now back to Microsoft putting Windows on top of Linux. Linux is better, faster, stronger than whatever is living underneath XP now, right? Performance would improve. As Mike Class points out, by not having to develop its own OS, Microsoft could also save money. They wouldn't need however many people are presently devoted to maintaining the underlying OS that isn't supposed to be there."
Some interesting historical trivia, but also a surprising number of spurious assertions/conclusions. Apparently Cringely hasn't reviewed Show-Stopper!: The Breakneck Race to Create Windows NT and the Next Generation at Microsoft lately.