Importing namespaces in XAML is different in .Net Metro applications compared with WPF. The difference is subtle and caught me unawares…
In WPF, one imports a namespace using.
This has changed to :
Note the ‘using:‘ rather than ‘clr-namespace:’
So its similar to syntax of import statements in c# code behind. The bonus is that you no longer need to specify the assembly name ( it is handled for you automatically).