Microsoft Exchange tasks
It would be great, if this is supported : https://together.jolla.com/question/1289/to-dos-in-native-calendar-app/, to be able to synchronize tasks from Exchange. It was a great feature in Nokia N9 which allowed for instance to synchronize tasks from toodledo via NuevaSync or any apps with todo apps.
From my viewpoint, this is the best behavior to open the world of GTD or basic tasking, and well with the Jolla idea of basic services provided to applications :)