From Tim Stevens at Engadget

"Disjointed is the key word that comes to mind after you spend some time with Windows 8. As a tablet OS, if you can keep in Metro land, things feel good. Very good. The gestures are a bit more complex and less intuitive than we've seen on other tablet operating systems, but more savvy users will appreciate that. That said, Windows is still primarily a desktop operating system, and once you get to that level the cracks in the foundation start to show."

Windows 8 is clearly a very big undertaking by Microsoft.  Not only do they want to show a fresh and innovative followup to the highly successful Windows 7, but they also want (and need) an answer to the iPad.  Can they really pull off a "one solution to rule them all"?  Early reviews suggest it will be an uphill battle.  (Mr. Miyagi's "Walk on the Road" parable comes to mind, relative to Microsoft attempting to serve two masters: Metro-Style Apps AND old-school Desktop Apps.)  It's also hard not to think about Microsoft's track record with "every-other-OS-release" (skip them).  Still, you have to believe there is a solid case to be made for a single OS strategy.