Some banks are paying back their part of the $700 billion in TARP loans -- with interest. But challenging questions remain. America's banks that were rescued as "too big to fail" are now bigger than ever, but smaller banks are failing fast. What's the connection? With just four banks -- JP Morgan Chase, Bank of America, Wells Fargo and Citigroup -- now issue half America's mortgages and two-thirds of its credit cards, do consumers still have any choice? Are the institutions that put the entire economy at risk being rewarded? Will it be harder than ever for the government to wrestle them down to size?