This looks like a very interesting re-think on how we handle email.
Actionsteps solves the flagging problem, where every email you know that you need to respond to is of equal importance.
With Actionsteps you’ve a great tool that just complement your existing GTD workflow. Just one click and you added an Actionstep with a priority. Read the full concept for more information about how Actionsteps work.
You can read a bit more about the background and concept in this post.