Surface Pro Extended Battery Idea

So I know there have been rumors about there being a cover that adds extra battery life to the Surface Pro in the style of an Asus Transformer. But I was thinking that the Pro is pretty thick so its gonna be kind of top heavy. My idea was that what if the covers maybe could be attached backwards. What I mean by that is how you attach it now the keys face the Surface screen when closed, but what if you could turn them away so they face up and there was some sort of pass through where you could attach a display as thin as an iPad or w/e the thinnest tablet is right now to it. The display would just be pixels and battery, so you'd still get your extended battery and it wouldn't be top heavy. It would operate more like a laptop since the Surface would lay on it's back its screen would shut off and you'd have a display you could adjust. I know my ability to describe things kinda sucks so I may try and mock something up to show what I mean later.

Alternate idea to the cover with a pass through is a separate display that has a touch or type cover permanently affixed to it, like a part of its design. Then you magnetically attach it to the surface the cover drops down to reveal the keyboard, the Surface tablet display shuts off the extended one turns on and you now have two batteries. Tell me what you guys think and if you can even picture what I'm trying to say.