--Windows 8 is not Windows, it's a new operating system with Windows 7 compatibility tacked onto it.

--Although Windows 8 looks pretty and is great for tablet-style content consumption, I question its benefits for traditional PC productivity tasks.

--Big OS transitions like this one traditionally cause users to reconsider their OS decision and potentially switch to something else.

--Microsoft has worsened the risk that people will migrate away from Windows 8, by disabling some key features of Windows 7, and mishandling the consumer "preview" program.

--However, people won't necessarily abandon Windows because it's not clear if they have a good alternative to it.

--Apple could provide the best alternative if it chooses to. This might be Apple's best chance ever to stick a fork in Windows.

--If Windows 8 is even moderately successful, it could weaken Google and the big web services companies. The trend toward bundling web services into the OS is potentially very disruptive to the web community, and they should be quite worried about it.

--If you're a PC app developer, you should probably hold off on Metro because it's not clear how quickly its user base will grow.