Other than the superhero himself, 'batman' is used as a term to describe something cheesy and usually old school, but still cool - something that is 'camp'. (i.e. listening to certain 90's music, watching certain old television shows, etc.)
Michael: What the fuck is this shit, Richard?!
Richard: This? This is Kurtis Blow!
Michael: This shit sucks, and it's super old!
Richard: You're kidding me. This shit's batman.
Michael: Yeah, maybe five years ago when listening to 80's hip-hop was cool.