SEC Chair Mary Schapiro (L) and Futures Trading Commission Chair Gary Gensler (R) testify before the Senate Banking, Housing and Urban Affairs Committee on Capitol Hill May 22, 2012 in Washington, DC. - 

If you wondered if lawmakers already took care of preventing another big meltdown, the answer is not exactly. Congress left many thorny details to the SEC to sort out -- which is why advocacy groups say the future course of Wall Street's leading regulatory agency is so critical.

"They have huge responsibilities writing the rules to respond to the financial crisis. The bulk of that is still unfinished," says Barbara Roper, director of investor protection at the Consumer Federation of America. She says the outgoing SEC chairwoman had a tough enough time trying to break the logjam between three Democrats and two Republicans. The commission will be evenly split with Schapiro's departure.


"It would seem that the best we can hope for is a stalemate," Roper says. 


At the advocacy group Better Markets, Dennis Kelleher says naming a permanent replacement should be a top priority for the Obama administration: "What we really need is a fresh face who is strong enough to lead that agency in a way that we haven't seen in decades, really."


Until then, he says, key financial reforms -- on such contentious issues as money-market regulation and high-speed stock trading -- will likely remain on hold.