Buying a house in an adult community at this time is probably not a good idea for two reasons: First of all, in most areas in NJ, house prices are anticipated to continue to decline, but only for the remainder of this year, maybe into early 2010. But, adult communities in NJ are really taking the hit because retirees are leaving the state due to the high cost of living here, specifically taxes!!! They are going to places like North and South Carolina where they get a lot more bang for their buck. So, if you are concerned that if you buy now you may not be able to sell in the future, you may have accurate predictions.
But, if you move into a single family home or condo, it is not the same scenario. While prices are declining, they will level out and improve again.