Ah, but obsolescence ain't what it used to be. I use a double-edged safety razor because I'm a cheapskate. I use a fountain pen because I like the way it writes. In a world of six billion people (is it still only six?), I'd bet we'd actually find very few things that were truly obsolete and simply never seen anymore.
I think the reports of the death of desktops (and "standard" OSes) are greatly exaggerated. I've no doubt they'll outlive me.
I would be hard pressed to name one person I know who has a personal desktop. They all use laptops. Soon, information will be delivered over a variety of devices as we are beginning to see.
I work for a Fortune 5. No one uses a desktop in my department. Laptops. Some folks are primarily using their Blackberries and iPhones for everything except presentations, which they have others develop for them.
I also use a safety razor, because it is just better.
And desktops and real OSs will be around as I mentioned before, because there more important things in the world to manage than which Facebook friend is within a five minute walking distance from you.