how Blender and Mecanim work together?

I have made some actions of my model in Blender, but today I found Unity 4 integrated the new Mecanim animation engine. How these two different ways to make animation collaborate with each other? It seems that Mecanim has predefined some armatures(e.g. ‘Humanoid’), do I have to change bones to fit it in Blender?

(I have watched Unity Mecanim Tutorial but it didn’t mention about how external modeling tool work with Mecanim.)

Hi,
This could be handy :slight_smile:
http://www.youtube.com/watch?v=Z9iUm2llVPc