Just a quick bit that I'm sure I will revisit later, but that I wanted to get out there sooner...
When embedded forms are saved, if you want to hook into the form save for the embedded form, use the saveEmbededForms function as save or doSave is never called on the embedded form.
The embedded form has it's saveEmbeddedForms function called, and then $form->getObject()->save().
I need to get in touch with the Symfony devs and see if we can't get some clarification on this setup in 2.0, as this "smells" wrong, but maybe it is just me.