It would be hard to imagine them going lower than the present. I would say they are artificially low in an attempt to keep the "values" of real estate from falling further as most residential real estate is still overpriced.
I would also assume that they will go up and then back down in the near future. Up a bit to convince people to buy NOW and then back down again when that doesn't work well enough.
It is probably the best time ever to refinance a house. Rates are low and the other costs will likely go up.
The best time to buy one is sometime in the next few years depending if you are looking for the best price or the best financing.
