Me Thinks :
a LOT of people in this world have had PC's for a long time,
and there is a change happening, one that scares and frightens those people who have all been used to being young and of the 'PC' eara. the fact is: they need to allow the new and brave through...!
its better to risk and die, than to do nothing and fade away (eh MS?).
office nees to work in the cloud and on tablets : fact
people will continue to use desktops etc : fact
its the private market MS is after, Apple have been grabbing that market (and google) in droves. and MS want a piece of that pie, at the end of the day metro is only a different menu and on by default when you log in.
(ok i personally aint to keen, but on a tablet it would work well i could see it as an ipad replacement (maybe/ish), when it gets some apps on it etc..)
there WILL be hacks making it more customisable, and it will settle down and people will cope, you will get used to it, but also statistically something stupid like > 50% of computers will be mobile/touch based by 2014
(i forget the actual stats, but its something stupid like this)
so in all real terms the desktop is suddenly a second place and mobile gets the extra effort.
MS knows this and is betting big on this, i say good on them.
last point
you know, metro is not aimed at Buisiness right? Win7 is still the buisiness software of choice, people have only just moved to it, they aint gonna budge just yet, MS know this, so is this a window of opertunity to try and grab the personal tablet market. it makes so much sense. i would HATE to use Metro at work, in fact i just dont think i could. but this market place is static, and flat line, why would you move again now. tablets is where the money is at.
if you were MS what would you have done? copy apple? stay the same? create a new menu for office, add a few tweeks, and say, look how dull we are? you would complain about that too.
more positivity people come on pleeeaaase...