I finished studying the code of Jounce. It is an astonishing work. Really.
You take Prism, Caliburn, Caliburn.Micro, you mix them and shrink them to get the essential for a size near the one of MVVM Light and you get Jounce.
So, perhaps the name should have been "CaliPrism.Micro Light" :-)
Real big thanks to Jeremy for your incredibly lucid and efficient synthesis of all those frameworks !
And thanks a lot to share this code with the community.