I have started learning about Windows 8 Store Apps.
I recall from Silverlight and WPF programming earlier that people adapted the MVVM concept and now I am not sure if
I recommend http://stylemvvm.codeplex.com, It's written from the ground up to support Metro projects (C#, C++/CX, HTML/JS). It includes a full IOC, implementation for ICommand & Attached Command Behaviors, Services for Tiles, badges, Toasts and Charms. It also includes a nice Mediator class that is dispatcher aware. Plus a number of visual studio templates to help get you started.
Note: I might be biased since I wrote it :)