If a recent Microsoft Job Listing is anything to go by then Windows Phone users could very well see Windows 8 and Windows TR apps hitting their handsets in the future.
Do you wish the code you write for Windows Store apps would just work on the Windows Phone and vice versa? If so, then this is the role for you! We are the team leading the charge to bring much of the WinRT API surface and the .NET Windows Store profile to the Phone.
According to the job post this is very much in the pipeline and the fact that Microsoft are throwing together a team suggests that it could be sooner rather than later.
Via: WP7 Connect