Microsoft's Metro design language is moving into the mainstream with Windows 8.
There are several online references that talk about the theory of Metro design, including the wikipedia page Metro Design Language (Wikipedia) and the Windows Phone 7 Series UI Design & Interaction Guide, a pdf linked from the Windows Phone 7 blog.
With public availability (from February 29 2012) of the Windows 8 Community Preview (aka Beta), we can now get our hands on, and interact with, Metro style desktop applications for the first time.
This opportunity gives us the chance to see how Metro style has been practically implemented - to identify practices work well (and which should be emulated), as well as practices that work less well (and which should be avoided).
What lessons about effective Metro user experiences can we learn from Windows 8?
Given the influence that Metro is having, where websites and conventional applications are becoming Metro-style, which features of Metro do we leave for use on Windows 8 and Windows Phone 7, and which do we reuse more widely?
[Editorial note: I'm seeking answers that will help myself and others to create authentic and effective user experiences in the Metro style, not a debate on whether Metro is a good idea or not. Please see my meta question to see some of my concerns in posting this question.]