Engineer-Poet, who occasionally comments here, has a provocative post up at his own blog, The Ergosphere. In "the Triumph of Exurbia," E-P posits that a serious peak-oil collapse scenario could actually result in a world in which exurban sprawl -- the medium-lot mcmansion communities well outside the urban core and suburban ring -- is a preferable place to live. The reason? One could become close to self-sufficient for food and, possibly, energy on the lots typical of exurban areas.
The big problem would remain getting around. Here E-P doesn't argue that the current set-up, with a bit of tweaking, would suffice, and argues again for plug-in hybrids as a critical solution.
I'm not sure the scenario works, but it does suggest an interesting opportunity should some of the bleaker peak-oil conditions look imminent: people who know how to turn golf courses and back yards into productive spaces will be in great demand.
The resource value of the land is a good and useful point to make, but the farming and fuel production sounds like a lot of work. I suspect this approach would work only for a select few... but it would be cool to see somebody try it.
Suburbs existed long before cars did and they will exist for as long as we have cities people wana work in but not live too near.
As for getting there and back its not realy a question of if but of how we will go about recombobulating our systems to handle oil reaching its zenith.
Now cities... they might be in trouble simply because of cost of living. The cost of living in a city is high because the transport costs and maintenaance costs are HUGE. Oil zenith will make this cost delta larger and that will in turn crack many old decayed cities that simply dont have the money base to pay for themsevles.
Still slum cities and wage slave cities will expand greatly.