I see Windows 8 really taking off once Leap motion\Kinect 2\Gesture devices are released and showcased. While touchscreens are all the fad for portable devices, the chocolate or pb&j smear on my screen is less than desirable. Smudges aside, when you have a stationary device would you prefer to walk up and touch it, or just wave your hand at it?
They (microsoft) should have held back on Metro until it (and its ecosystem) were truly ready. In forcing people to use an immature Metro, it has left a bad taste in many of their mouths. If they had made this the default, but optional startup screen everyone would have been happy. Windows phone 8, windows 8, kinect 2 for pc, and xbox (720) should have all been released back to back to keep momentum and customer visibility. I think Microsoft missed a couple opportunities here.
Sometimes to save your castle, you have to burn a few bridges. Microsoft has been unwilling to commit to this and is paying the price. As a tablet, the Nexus 7 / kindle fire / ipad mini are all at a price point that Microsoft and its hardware partners refuse to compete in. This imo has caused slow adoption for Windows 8 tablets. The original MSRP of $200 for windows RT tablets would have blown the market open for Microsoft. Again opportunity missed, but this one was more costly.
The curtain is far from closed when it comes to Windows 8, but its certainly off to a less than stellar opening act.