I'm going to start a new WPF
project and I'm considering to implement it by the Metro UI
approach.
As this UI isn't yet popular, and also my project will release in early 2012, does it worth to implement Metro UI in my application or not?
What are the alternatives?
IMO, it is worthwhile because Microsoft is advertising it, a wide variety of applications will release with this UI, users are exited to use this new UI, and this is an opportunity that you can make for yourself.
In addition in the near future most of the Custom Control companies will make a new control for it just like Ribbon. I know that ribbon wasn't a complete UI but it shows that Microsot UI approacehs are worth to try