Mortgage rates are near an all-time low. They haven't been this low in at least 39 years. It is amazing that someone will loan me money for 30 years with a fixed interest rate of 4.5% and I can pay it back in depreciating money. With such a low rate, it is telling me that the market is not scared of inflation right now. It is just scared. People are willing to accept really low rates for the safety of their principal.
The bond market is probably a bubble. I would be surprised if rates did not rise dramatically in the coming years. But who knows for sure? Maybe we will end up like Japan. Japan has a debt-to-GDP ratio in the neighborhood of 200%. This makes Greece look fiscally responsible. But Japan's rates have remained low for 2 decades. I don't expect this to happen in the U.S., but I'm just pointing out that it's possible. In other words, don't short the bond market right now. If you have a mortgage and can refinance it at a really low fixed rate, do it if you aren't planning to sell anytime soon.