Moving from desktop to mobile keeping compatibility (with a huge base - a challenge no one else had - possibly only nokia transitioning from dumb to smart) isn't a trivial problem by any stretch of the imagination. They took a swing in a very unpredictable and hyper competitive market. It had to be a big swing and it didn't work. Its a shame cause I think their dev tools/platform/languages are solid. I enjoyed working with C#/WPF/xaml in comparison with Android/java/flash and the current hodge podge of web tech.