I agree that in certain regions there is definitely a bubble; however, unlike the stock market, real estate bubbles have always been regional. I know that where I live, every projection is that it will be at least five more years before there is enough housing to meet demand; the saturation point and whether or not the homes are primary residences has more to do with it than most other factors, places like Florida will probably get hit hard because in many cases the run-up has been in condos used as second homes, many people will be willing to cut there losses and sell. But in areas where people work and the average home is still affordable to the average resident, there is not alot to worry about.
Even the times when there have been nationwide dips in real estate, it has always been a relatively small percentage and it has always come back. When the Nasdaq collapsed, many people wound up holding worthless stock in companies that no longer existed, that is simply not the case with real estate.
Interestingly enough, what is still selling briskly are condos and townhouses - not single family homes. It's the single family homes that are taking a beating. I've been watching that since we had planned to upgrade this year ... but when I saw stuff sitting on the market, single family homes ... and following up on what they sold for ... it was better we waited till the spring.