Last week we spent plenty of breath on Sandy Weill, the former head of Citigroup. Back in the '90s, he fought for his and other banks to grow huge and complex. Then last week Weill goes on TV and says: "It's time to break up the big banks."

Sandy Weill, who engineered Citigroup and the creation of megabanks, says big banks should be split up. Will the debate now gain traction?