In the past year I renewed two regular CD's before they matured without penalty. One was a five year that I got in April 2008 and by June 2008 the rate had gone up about 1/2%. The other was a five year CD that matured in April this year. As I was watching rates fall I decided to renew it in January. I felt like a fool renewing for a lower rate but not as low as the rates ended up in April.
I think it all depends on your banking institution if they charge you with a penalty. My CD's are in a credit union (not PenFed). The new terms were the same as the old one, just a different rate.