Official Microsoft comments on XNA support so far has been that “XNA is fully supported” so existing games will work on WP8. however nothing was said about developing games for Windows Phone 8 in XNA. Today I explicitly asked this question and was clearly told NO.
This does make a lot of sense purely because Windows Phone 8 share codebase with Windows 8. The available choices for developing Metro-style apps for Windows 8 includes .NET, C++ / DX and HTML5 / JS. It does not include XNA. If that is true and accepted, we can also accept that Windows Phone 8 pure development (ie not targeting earlier platforms) will result in XNA not being available.
So where do that leave us.. According to Microsoft.. all engines and all big games companies wanted to stay native and hence the choice as such.. Considering most development on Windows Phone is hobbyist creation that seems a bit risky.. I don’t know many hobbyist developers who code C++ games.. XNA makes it easier and is an ideal choice… Of course it can be done in XAML / .NET..
The likely course of action short-term ? thank heavens that we have MonoGame.. They support for Windows 8 and I hope they will added support for pure Windows Phone 8. It allows you to write in XNA and it outputs WinRT compatible code (I presume using XAML /.NET or C++ / DX)
Let me know your thoughts on this..