Which bit is the possible Batman reference?
When Amon ambushes Korra at Aang's statue and has the opportunity to seal her bending, but doesn't since that would make her a martyr. It made me think of the "your punishment must be more severe" part from the third TDKR trailer. It's not an uncommon trope/plot device, but the proximity of Korra + TDKR, and similarities between Amon and Bane, with Korra sort of being a crime fighter make me think that.
Also, the credits in Korra where the "camera" zooms in on Republic City over the water reminds me of the first few seconds of:
