Smart[er] Lists: Subdivision of Views
Today, Week and All are very useful views that allow for smart viewing of reminders. However, not all users will have a sole purpose for using Wunderlist, and instead have many different uses (hence, lists): for example, I use Wunderlist for work purposes and home purposes. Work can be further divided into projects, admin, teaching; home can be divided into todos, food shopping, movies to watch. The last thing a person wants when at work is to be distracted with much cooler things that they will be doing in their personal time; the last thing a person wants when at home is to be distracted by the chores of work.
My suggestion is that greater flexibility is incorporated into smart lists. Instead of just showing All, allow users to have a view that combines defined lists.