Here are some great Windows Store app samples shared by the Microsoft Most Valuable Professional Sara Silva. She is focusing on Windows Store app and Windows Phone development.
Sharing Code between Windows Store and Windows Phone App (PCL + MVVM + OData)
Creating portable code in Windows Store Apps (PCL + MVVM + OData Services)
Consuming Odata Service in Windows Store Apps (Include MVVM Pattern)
Localization for Images and Assets
Slide Share Sample
Displaying DateTime objects in a localized application