Writing something myself is an idea I have brewing in the back of my mind. But it's not something I have any clear ideas about. I have no idea how it should work, only a vague idea that it should be as seamless to my daily routine as TaskWarrior is right now.
But I'm trying to collect notes on how I use Wunderlist and TaskWarrior. Maybe in a few months I'll have a better idea of my usage patterns and then I can come up with something that I'd love to use everywhere.
Do you have any ideas on what you'd like to write yourself? I could get ideas off of you. :)