Treasury Secretary Henry Paulson struck an optimistic tone on Sunday when announcing the federal takeover of Fannie Mae and Freddie Mac. “Today’s action should accelerate stabilization in the housing market,” he said in a statement.

Analysts, economists, and industry-watchers don't sound so chipper.

While few will disagree with Paulson that “Fannie Mae and Freddie Mac are critical to turning the corner on housing,” many housing- and market-watchers are already arguing the merits of the GSE rescue plan.

"This is not a permanent solution--they've not saved Fannie and Freddie, what they've done is they've bought 15 months,'' Bill Ackman, founder of Pershing Square Capital Management in New York, told Bloomberg News Monday. “It's a band-aid. They haven't permanently recapitalized the companies.''

Bank of America CEO Kenneth Lewis, who reportedly consulted with Paulson on the Treasury plan, expressed a more positive outlook. "This action should lead to an increased availability of mortgage financing, which will help achieve stability in housing,'' Lewis said via e-mailed remarks according to Bloomberg News.

With the backing of the Treasury, Fannie and Freddie should also see the cost of acquiring debt go down, which could lead to lower mortgage rates, suggested Brian Bethune, chief U.S. economist at research firm Global Insight, who released a short analysis of the takeover plan Monday. Bethune argues that 30-year fixed mortgage rates could move down to close to 6 percent within weeks and possibly fall below that level by 2008's end.

“The prospective decline in mortgage rates should provide a needed shot in the arm to the U.S. housing market, as it would provide another boost to affordability beyond the sharp declines in prices that we have seen in the past two years,” Bethune said.

Financial services firm UBS also backed the notion in a report released yesterday that mortgage rates could come down and forecasted that the impact of the GSE rescue could reach far beyond mortgage rates.

“We expect this effort to create a near-term benefit for housing, as reduced capital constraints at FNM/FRE should drive lower mortgage rates, better affordability, and improved buyer sentiment,” UBS said in its report. “In turn, this should help slow the rate of deterioration in the broader housing market.”

But Ivy Zelman, CEO of Zelman & Associates in Cleveland, asserts that the impact to home builders will be marginal. While Zelman acknowledges the potential for a reduction in mortgage rates, she told BUILDER Monday that the current credit quality of potential buyers and down payment requirements will still hamstring builders looking to make sales.

She also noted that the Fannie and Freddie bailout will not help home building companies seeking AD&C (land acquisition, development, and construction) financing. While banks will be able to sell new mortgages to Fannie and Freddie, the GSEs aren’t buying construction loans. At the same time, the performance of AD&C loans are quickly deteriorating, meaning more builders are giving their assets to their banks.

“Charge-offs are expected to accelerate, and more builder failures will result in more assets that (banks) will have to take into their REO bucket,” Zelman said. “We’re going to have a lot more bank failures and a lot more builder failures before they come up with a new stimulus package related to that piece of this housing problem.”

But when Zelman noted how much the federal government has spent to bail out Bear Stearns ($30 billion in loans to JPMorgan Chase), and the housing rescue bill (up to $300 billion in mortgage relief to home owners), she questioned whether the government can really afford to provide any more lifelines to housing. “The idea that they are going to do a lot more than what they’ve done so far, and increasingly put us into a darker black hole, I think is really just over the top with optimism,” she said.

(Many builders and housing analysts have been calling for tax rebates for home buyers.)

The cost of the takeover will certainly be huge. Former Federal Reserve Bank of St. Louis President William Poole told Bloomberg Radio Monday that the federal government’s move to prop up the GSEs was “a stopgap to try to prevent the mortgage market from falling apart.” Poole estimated the Treasury may need to cover as much as $300 billion in losses related to the plan.

But no one really knows what the final costs--or consequences--will be. “The Treasury's move does not answer the question of what ultimately happens to the GSEs – management control goes to the regulator, but the next Congress will ultimately have to decide on their long-term role in the mortgage markets,” Bethune said.

Ethan Butterfield is senior editor, business, at BUILDER magazine.