I think the UI improvements alone (desktop search, Aero Snap) are worth the price. Isn't this how Apple justifies charging for new versions of OS X? I still use XP from time to time and 7 is far and away a better experience. FWIW, I think it also provides a better experience than OS X, although, sadly, without the benefit of a POSIX layer.
"blame the utter lack of progress by MS"
It's not like MS has been sitting on their hands of late. Kinect demonstrates this. Windows 8 demonstrates this. I just don't think there's an appetite for MS progress or innovation. What people like about Windows computers isn't (and hasn't been for a long time) Windows. It's pretty hard to innovate when no one wants what you're selling.
To be fair, I don't "blame the users" for this. When MS had a tight grip on computing, they did little to make their products more compelling and they are realizing the consequences of this now: Windows' name is mud.