With a U.S. about-face on mortgages, is a bubble coming?

An about-face by the Obama administration on mortgage lending is causing some to ask if we're looking at deja vu all over again.

Mel Watt, the director of the agency which oversees Fannie Mae and Freddie Mac, made his first public speech since taking on the role in early January, noting that the agency won't shrink its footprint, marking a break from the direction of his predecessor, Edward DeMarco.

Watt also said the agency won't reduce current loan limits because of concerns about how that "could adversely impact the health of the current housing market," according to his prepared statement. The new stance marks a shift from Washington's approach to the housing market following the 2008 crisis, but has sparked some concern that looser standards could lead to another bubble.

"I don't think it's FHFA's role to contract the footprint of Fannie and Freddie," Watt said at his address at the Brookings Institution, according to Reuters. "Our overriding objective is to ensure that there is broad liquidity in the housing finance market and to do so in a way that is safe and sound."

Right now, Fannie Mae and Freddie Mac guarantee about 60 percent of home loans, and they will buy loans as large as $417,000 in many markets and as high as $625,000 in high-priced regions.

With Watt's new direction for the agency, it's possible credit could become easier to access. While that might be positive for homebuyers and home builders, it also raised concerns about how the move will impact the overall housing market and prices.

"At the margin, keeping loan limits high does help support home prices," Zillow chief economist Stan Humphries told CBS MoneyWatch. "Home prices are rising much more quickly than they should be," even though they remain affordable in many markets.

But lower rates are "are already creating affordability issues in some markets," such as San Francisco and other high-cost cities, he noted. Lower rates often incentivize buyers to bid up prices, because the lower cost of borrowing makes homes seem more affordable.

Still, Watt's comments are more about "what the future of mortgage financing will look like, instead of replaying the housing bubble," Humphries said. The downside, to his view, is that there will be "less opportunity for the private sector to innovate with new mortgage products."

"It seems a bit odd for one of the most pro-free enterprise economies of the free world" to have a federal government so involved in lending, he added. "The vision is one where we can't even trust the private sector with any amount of innovation, so the government should do it all."