Yup this year marks 75th anniversary of The Dark Knight himself. For that occassion DC plans lots of stuff going on - for me the most notably are two things, namely two animated shorts - one from Darwyn Cooke, who is working on Batman Beyond short, the other is from Bruce Timm himself doing somethig in spirit of Batman in late 30’s / early 40 and it looks amazing so far.
 
So let me celebrate this anniversary my way, with healthy dose of ponies :P  
Each of mane 6 wears uniform that I remember most:
 
Applejack wears the suit first seen in Superman: Red Son - yes, USSR Bats is in the house xD
 
Twilight wears my personal favourite version - costume from Batman: The Animated Series, although the resemblance may not be that obvious. Well I tried ;)
 
Rarity wears the very first Bat costume - going back all the way to 1939 ;)
 
Rainbow Dash - oh I had to give her something special - she wears suit from Tim Burton’s first Batman movie (1989) the-no-neck-turning batsuit. As You can see, she loves it :P
 
Fluttershy - given the incident in Bats! - recieved the Vampire Batman look seen in Batman: Red Rain, Bloodstorm and Crimson Mist.
 
Pinkie Pie - wears the suit from Adam West - given the wackiness of that Batman intepretation she would fit pretty well into role :P
 
Yeah I could add some Dark Knight Returns suit - maybe I should’ve drawn Granny Smith for tha