I'm using Windows 8 x64 RTM, but when I open the mail app and compose an email, then pick contact using the "+" button:
I'm greeted with an error message from people hub:
This app uses email addresses and none of your contacts have any. Open the People app to add this info to your contacts.
However I do have contacts that have email addresses:
How do I properly connect the People app to the Windows Mail App?