According to the New York Times now is the first time in 30 years the median mortgage payment is equal to the median rent payment. This can be seen as a good time to buy or a good time to pick up an investment property as the housing market has gone through a major correction over the past few years.
While lending rates are historically low, buying a house is harder because there are higher lending standards, 20% down payments are required, and your income to debt ratio needs to be fairly high to qualify. Those buyers that want a house (and can qualify) have already bought a house most likely.
There are a few different forces at work here: historically low interest rates, the fallout of the housing market (including mass foreclosures), and the increase of rent payments. Some parts of the country have had lower mortgage payments than rent for quite some time. Taxes, maintenance, and insurance are part of owning a home but those costs are passed on in higher rent payment to renters.