I have made exactly that argument on this site a few times. Dense, downtown condo concentrations in San Diego and elsewhere may be a market disaster today, but their utility (and value) will be very much appreciated in the years to come.
Global financial and credit tomfoolery aside, a common response to the mentality that downtown property values will recover due to demographic and energy concerns is that such a living arrangement is a ‘young professional’s thing’ and that ‘families will seek out the suburbs’. This directly misses the point. Attitudes will change if circumstances compel them to change; families, kids and all, will learn to live without wasting so much energy on transportation.
Of course, this is all predicated on downtown actually being a walkable, livable community. My experience in downtown is limited to a few Padres games, and it did not strike me pleasantly walkable. Anyone here living in downtown have insights on this?