That's very nice. You should post this on the Wizards forum as well.
[MENTION=85179]ren1999[/MENTION]
I made another mock-up..
That's pretty class, I don't see why keeping fluff first means we have to have ugly ass stat blocks that are a pain to read(and I know the one Mearls did was a first go and not a finished article).
I seen mention that 2e had a spiral bound monstrous manual (can't find a picture but this maybe? or maybe I'm going crazy) For the way I use the Monster Manual I would love this format and if 1 whole page(front and back) was given to a monster you could add build options on the back. So details on levelling your standard goblin grunt and how you could turn him into a goblin chieftain or spellcaster (with new attacks or whatever).
Can't say if this would actually work just a thought.