@felix9 , so far, it seems it's only possible to use DirectX with C++ if I'm not mistaken. I didn't dig into the details of C++/C# mixture but for us, we already use another framework we developed on top of XNA to ease our porting from/to iOS and/or Android so if there is any such possibility, we might go that route as well though still means extra work.
@AndyC , with Windows 8, it's more about Indie devs rather than big studios. Windows Store, as similar to other store implementations, allows the entry barrier to reach a global user base much lower than before. At that point, for small studios such as us, it's more important to being productive than using the lowest level of API, unless you are developing something that pushes the hardware to it's limits. I know that XNA didn't change the world of Windows Game development in the past but with the reasons above, it's now much more important and I bet if there was (or will be) XNA/C#, it'll be used to develop games much more than DirectX/C++ in Windows 8 Metro Games
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