http://io9.com/5396278/what-if-moviemakers-swapped-franchises
Pros: You'd get a new Batman movie every two years, even if Michael Bay would complain and tell people that he didn't want to make it but the studio offered him so much money he couldn't say no. Plus, with Bay attached, you know that they'd get to Catwoman as soon as humanly possible instead of this whole "I am a nihilist Joker" crap from The Dark Knight.
Cons: Kurtzman and Orci would probably take their Daddy issues (Fringe's Walter/Peter complicated relationship, Star Trek's Kirk trying to live up to his dead father's memory by self-destructing but then coming through as the hero he was destined to be, even Transformers' Optimus as Tough-But-Fair Robot Daddy to Shia's Sam Whitwicky) to pop culture's most parent-obsessed character, leading to the risk of a third act emotional breakthrough where Batman cries. There are enough Batman characters to make Revenge Of The Fallen seem understaffed, and the various personality tics of said Batman characters could lead to more unfunny schtick like the Twins and/or Jazz from the Transformers movies. Michael Bay possibly already sees himself as Bruce Wayne. Also, there's every possibility that the movie would make no sense whatsoever (See: Transformers, Transformers: Revenge Of The Fallen).