So are you saying to simply pay the minimum?
I'll put it to you this way. I refinanced my 30-year mortgage at 3.25% recently. That is about 2.5% once you take the tax deduction into account. When someone is willing to lend me money at the rate of inflation my only question is "how long will you let me have it?" because the real cost is zero. And on top of that you get extra liquidity.
I am very much looking forward to paying this mortgage for the full 30 years. I wish I could have gotten it for 100 years instead.