This sounds to us like a logical progression of an internal strategy taking place – we already knew that the forthcoming console runs two engines – the Xbox OS runs games and a separate Windows 8-based OS executes apps. Once the massive grunt work involved in ensuring your apps reach as many users as possible across different platforms goes the way of the dodo, we can definitely see developers wanting a piece of the action. Enticed? Guggenheimer continued teasing developers by entertaining the notion and suggesting you get a 'head start' by developing apps using Windows 8 tools that will supposedly be almost identical to those for Xbox One.
Hit the source for the full Day 2 Keynote speech.
source: Channel 9 (video) via Neowin