You may or may not have seen the Beer Buddha’s annual Beer Geek’s Guide to Mardi Gras 2012 Edition, but you should definitely check it out!
It has an overview of beer bars and stores in the city, listed geographically. Most of these places can be found elsewhere on this site, but this is a great Carnival-centric listing.
Any good places to celebrate Mardi Gras with a good beer that was left off? Comment here or there!