OWN is the discussed notion: In the article terms I agree 100% with Jeff.
If your work is mobile, yes you're going to need one. But the title was that "I'll never own a laptop". So for my personal use I don't think that I'll ever need one and the main reason is this: the laptop is an evolution stage that will eventually lead to home computers with flat screen, better input devices etc. And if you have kids you can say goodbye to 4000 that you paid for it.