As a Windows 8 developer, the most frustrating part of WP8 is the lack of compatibility for native HTML5/WinJS apps. For me, this was the best thing about Windows 8. It made building apps easy and fun. The most ridiculous thing about the whole thing is that the HTML5/WinJS apps are completely responsive, and you pretty much have to build a mobile version of your app to support "snap" mode. So, they could easily have a write once, run anywhere model if they just supported native HTML5 apps in WP8. Sorry, /rant.