[svas]

Not sure if you have tried doing this. In practice, it's quite painful as you need to have a separate visual studio project file for each platform (phone vs tablet).

Further, the Phone implementation of WinRT is a subset of the tablet's, so sticking to the WinRT API alone isn't enough. Complicating matters further, the phone lets you actually use a Win32 subset which is not allowed on tablet.

This (appears to atleast) unify everything towards more of a write once, run on all windows platforms world.