Squad should release a Scenario editor to the community. It would:
1) provide a wealth of fresh things to do.
2) stop us from relying on challenges (which are almost depleted).
3) let us start later in the career game. (tech tree and science discovered)
4) allow us to start with off-world facilities.
5) create scenes from our favorite movies/books.
and much much more.
It should have a slick UI to make scenario generation easy.
http://bugs.kerbalspaceprogram.com/issues/8804
I almost posted this under feature requests, but I thought it would be more appropriate here as it might change the name of the topic.