Get ready to smile.
5. The Price (at least until January)
Just because Windows 8 looks and behaves differently than its predecessor, it still runs all the applications Windows 7 did. On the plus side, the entirely new Metro UI opens up a new world of secure applications from the Windows Store.
Best of all, it's still Windows, so all of the things IT administrators do with securing systems and setting group policies are still there...with even more flexibility than before.