W8 could be another Vista or Unity. It already has people lining up, for and
against. The Metro interface has many people worried. Like Unity it is
progressive, but it leaves desktop users behind. This its more worrisome for
MS because they have a large base of established users particularly in
business which are slow to adapt.
We live in a time of change.
Tablets and mobile devices are the future and MS is late in the game, but
their entry adds much weight to the argument that the age of desktop
computing is ending.
Many of us who grew up with desktop computers will resist to the end. Myself
included. It is way too much fun!

Unity is not alone. Lion, Gnome 3, Unity and W8 face the same challenge
which is to prepare for the future and at the same time not leave others
behind. Compromise inevitably gives mediocre results. You end up ticking
people at both ends. Striking a balance is tricky.

I would be interested in hearing from anyone who has used Unity and W8. I
don't expect them to be similar, but they are striving for the same balance.