Just to clarify this statement before people start thinking that I have contradicted myself here, you don't know what you don't know, and Michael Bay was only recently put through 'Transformers School' in preparation for the first movie so I'm not directly blaming him for the lack of content.
I would have liked to see more involvement from Hasbro in creating a documentary style '25 Years of Transformers'. What we have is a shameful plug for the recent movies (which is comical considering chances are you wouldn't be watching it if you hadn't bought the DVD already), with some G1 tacked on which feels like an after-thought.