Realtor Magazine April issue says, historically homes in USA have appreciate around 25-27% over a 5 year period. In the six years between 2000-2006, however, appreciation was 89% , nearly 15% per year on average, todays correction is a move back to stability. 
Makes you wonder if we are corrected already or more to go. Also we need to remember that the wages never increased 89% during 2000-2006, buyers keep buying because they were given all kinds of loans just to make them buy. 