I got my second Windows Phone (in spite of developing exclusively on iOS myself), and I don't miss most apps. It's amazing how many good third-party apps work with the cloud-backed apps I use on my iPad. Instapaper, Trello, Simplenote, etc.

In line with Microsoft's info-not-apps philosophy, I'd love for them to work with, say, Lyft, to integrate the APIs behind the app into Cortana - so I can have a similar experience as the Lyft Android Wear app. Extrapolate to all the apps that are UI layers for a web service.