Are you serious?
For the developer preview, the first thing I did was go "wtf????".
The second thing I did was use internet explorer to download firefox.
The third thing I did was use firefox to google "disable metro".
For the consumer preview, the metro interface cannot be disabled. I've learned the metro interface, and I have to say "wtf was microsoft smoking when they came up with the totally whacked interface where the screen keeps flashing when you want to launch a program. My desktop is now cluttered with shortcuts, so I don't have to go back to metro.
I've customised the metro interface so it has about 4 icons - desktop, firefox, control panel & steam.
Everyone criticised windows 7 for various reasons, but I only saw good ... I love win7.... But windows 8 is going to be brutal for microsoft, if they ship it with metro as default for PCs.
I like the improvements to the file copy dialogue, and I can understand the rearangement of the task manager (but don't agree with it), but metro is just stupid.
It has a few under the hood improvements, particularly for owners of recent AMD cpus that are not entirely conventional, so win 7 completely under-utilises, so it will provide a handy performance increment.
Also the move to replace shutdowns with hibernation, I don't like. I often install drivers/programs before I shutdown the Pc for the night, but windows 8 will require a restart, and then a "shutdown".