I totally agree that there's this very small, very insular part of the world that thinks it's dead, but that part of the world is apparently not working in large companies, or trading files with professionals in any profession other than design (e.g., try to find an Architect using Mac-based software -- they can't, because they couldn't trade files with each other or clients).
I'll believe MS is dead when they have, say, less than 70% of the world's computers running their operating system and when my corporate clients stop asking for files in Word format. Until then, they're just a monopoly that has massive amounts of power but that the cool kids aren't interested in.
It's like saying POTS telephones are dead -- they might not be interesting, but that's a big difference from being dead.