"From book sales, of course, we know that OS X is considerably hotter than Windows XP."
I usually dig what O’Reilly is writing, but here he should drop the crack pipe. Book sales reveal trends about books, and maybe the economy at large, but not operating systems. Case in point, after all these years, and billions of metric tons of books about Linux, this OS amounts to exactly 0% market share on the desktop, as independently demonstrated by the referrer logs of about every web site (I’d love to see Slashdot stats just for fun). Unless, by "hotter operating system," Tim meant "OS that failed to translate buzz into sales, because people weren’t impressed with what they saw," and now that makes a lot more sense.
I run Windows XP Pro on our two computers, and never did I feel the need to buy a book about it, yet I find it’s an excellent operating system. If you want to know about the hottest OS, you’d better check… operating system sales. For all the "switch" brouhaha, Apple isn’t going anywhere but sideways (ok, they’re doing fine in the notebook market). People anticipate Jaguar because everyone acknowledges OS X is sluggish. Apple is just borrowing from Microsoft’s book and selling a bunch of patches as an upgrade.
Tim adds he’s been doing a little research and checked Dell’s sales for comparison. Hello, this isn’t the Benevolent Dictatorship of Closed Overpriced Underperforming Hardware here, this is about the open PC market driven by Microsoft standards [*] such as DirectX. Brand names