FICO is overhauling its credit scoring formula starting in 2009. The new formula will likely affect whether or not you get a variety of loans — including a home mortgage loan. FICO plans to offer finer shades when reporting consumer habits, with the idea that one late payment in 36 months is less serious — should affect your credit score less — than four or five late payments.

Another issue that FICO is working out is piggybacking. Sometimes a child uses his or her parents' credit, or a spouse uses his or her partner's credit, to help build a credit profile. This is accepted. However, abuses have been detected by services that pay those with good credit to allow an "authorized user" to piggyback just to get a bump in score. FICO insists that it has figured out how to distinguish between these practices.

Watch your credit score very carefully in 2009. You could see some big changes.