Rep. Paul Kanjorski, the Pennsylvania Democrat who is chairman of the House Financial Services Subcommittee on Capital Markets, will hold a hearing Wednesday on the unpopular mortgage companies and their two-year-old regulator, the Federal Housing Finance Agency.

“This hearing to evaluate the performance of FHFA and the entities that it regulates will help us advance our ongoing efforts to rewrite the laws governing our nation’s housing finance system,” Kanjorski said.

This is hardly the first discussion of how to fix Fannie , Freddie , and the housing market that overwhelmingly depends on them for low-cost financing. Treasury Secretary Tim Geithner told Congress in March that he hoped to begin discussions this year on how to restructure the mortgage markets and the two companies.

A restructuring is badly needed, obviously. Together, Fannie and Freddie have taken $145 billion in federal aid and are expected to cost taxpayers at least that much again over the next decade.

But the government isn’t exactly chomping at the bit to destabilize a banking system it spent untold billions propping up. Accordingly, Geithner spent much of his appearance in March emphasizing the need to come up with a workable plan before the feds take action.

Not everyone shares his caution, however. Republicans led by Sen. John McCain, R-Ariz., even proposed an amendment to the Dodd bill that would have wound down Fannie and Freddie within two years.

It seems a bit optimistic to think you could wind down in two years a pair of companies that took decades to get into their costly fix, and the McCain proposal was rejected. Instead, the Senate agreed to study the issue.

This may not seem like the end of the world, but you’d be hard pressed to tell from the scathing press release from Rep. Spencer Bachus of Alabama.

“It’s been nearly two years since the government took over Fannie and Freddie and despite repeated assertions that something would be done, this is the best they can come up with?” Bachus said in a May 11 response to the McCain amendment’s defeat. “It’s pathetic, and the taxpayers deserve better.”

If you find this sort of discussion edifying, be sure to tune in Wednesday.