This seems to be the same chatter we had when Win95 came out, then WinNT, Win98, Win2000, WinXP, Vista, etc...
(yes I left a few out, but who needs to remember millenium?)
Nothing new here, MS is still going to be around even with the shift.
Not everyone likes working on a MAC. I for one hate it even though I have to use it at work. And most people still think Linux is command-line only. Of course when you show them what it really is nowadays, they go oooh-aaah, but still want to stick to something they know.