First it depends on the region. Coastal areas tend to be more volatile than the Midwest, as coastal areas are more investment driven. Midwest economics are pretty conservative, they tend to prefer cheaper housing payments on purpose. That being said, I don't predict much of a bubble anymore, as I believe people are buying to get ahead on inflation. They want to print money? More dollars floating around means more dollars used to buy things. Using less dollars today makes sense, as things will be " more expensive" in the future.
Mortgage rates are falling, and will continue to fall. Following the 40 year trend line, there is no reason to believe that they wont issue 1.5% MBS coupons in the future, and eventually 1%. They will do anything to save the market, and 1.5% 30 year mortgages will happen someday. In the Midwest, that means a cheaper monthly payment. In coastal areas where they max out their monthly payment, it means higher sticker prices for homes.