According to this article from the Real Estate Journal [Note: Subscription] , condo prices exceeded single family home prices for the first time ever in early 2005.
* Condos leapt to prominence after the 1961 Housing Act enabled the FHA  to insure mortgages on the units.
* 970,000 condos were sold nationwide in 2004
* 1 out of 7 existing home sales are condos
* national median condo sales price is $223,500
* national median home sales price is $218,600
Why are the overall condo prices higher than houses?
With the resurgence of urban areas and a decline in “nuclear” families (40% in 1970 to 24% in 2000), condos have increased in demand.
Areas of Concern
Now there is concern that the change is more than demographics, that condo prices are rising too fast [Note: WSJ Subscription]  as a result of speculators and investors favoring them over housing.
With great investor concentration in condos, could infer that the single family housing market has the potential to be less volatile in a market down turn.