Based on my understanding, I don't think the toolkit's dataGrid will work in the Windows Store App. From this link :
http://msdn.microsoft.com/en-us/library/windows/apps/br229571.aspx#xaml_language_capabilities
There are restrictions that would prevent the code from compiling, mainly in the "XAML language capabilities" section.
http://msdn.microsoft.com/en-us/library/windows/apps/br229571.aspx#xaml_language_capabilities
There are restrictions that would prevent the code from compiling, mainly in the "XAML language capabilities" section.