Regarding people spending ages looking for ways to shutdown the thing... why don't people just press the power button? :\
Personally, I'm in two minds. As with most, I don't like Metro at all - what were they thinking in not making it an optional shell? Little else in the GUI has changed, so it's not as though they've rewritten the core of the OS. You really should be able to fall back to the standard Start button, or if you are going to make things more intuitive for tablet users, then make it so it doesn't all-but alienate the desktop power user, or make the desktop more intuitive too.
That said, I'm not sure how much Metro is going to affect me. You can still pin your most frequently used programs, hopefully developers will develop tiles where they are of benefit too (and only where they are of benefit - I really wouldn't want to see that there's a new version of Norton out the moment I switch on my PC (not that I use Norton of course, but it's the sort of thing I can see them doing).
And you can still search for programs, and with one less key press too. Just start typing and hit enter. Sorted.
I will miss the most recent documents in the Start menu, be they either for individual programs (as in Win 7) or just the accumulative ones we've had for a decade or two now. I guess now that you'd need to open a program.
There's no way on earth that corporate users will upgrade to Windows 8 - unless there's some fantastic integration with Server 8. The only ones who will consider it will be those who can genuinely make use of a tablet and want to retain 'docked' use.