There are a series of proposals, mostly surrounding taxes and caps on size, leverage and presumably complexity. The first bullet point, a cap on size relative to GDP, is similar to the SAFE Banking Act, which failed in the 2010 Senate with 33 votes. They all sound like good ideas, though they received little-to-no GOP support during the debates.
Mike Konczal sorts through Huntsman plan to end To big to Fail. Wonky but worth a read.