Megrimlock

It depends what period of the future is specified, as I think the evolution of cities will be somewhat spiral. In the near future I think there will be a greater convergence of the main metropolises, with New York, Tokyo, Rome, Beijing, Bombay and London coming to resemble each other more and more closely as cities around the world all take on a multi-cultural slant incorporating bits and pieces from each other.

In time, though, as the rate of improvement of technology slows at least insofar as optimising urban convenience is concerned, the purpose of urban evolution may change. A reclamation of the unique characteristics of each particular city will occur, so that Rome builds a new Coliseum, London a new castle, etc. In the far future I think the future of cities will depend on the extent of interplanetary colonisation, which despite the restrictions currently on space programmes (not to mention the diminution of political capital to be gained from them in the current climate) is ultimately inevitable. Sooner or later interstellar colonisation will occur as some circumvention of the light barrier will be found. Unrestricted by the practical limitations of room and resources, cities will be able to develop organically and independently again, with less convergent influence from other settlements light-years away. I think that conscious cultural choices will then dictate how cities develop when the technology exists to pretty much build them to order. People will be able to live in a bustling uber-techno metropolis or a lazy quasi-medieval farming town. Obviously certain universalities will persists, as even those who wish to return to simpler times will be likely to retain medical technology and space travel to enable at least a minimal trade and communication level. Possibly the most popular would be a balance where small rural settlements were arranged around a pristine metropolis, with an agrarian theme but with all the benefits of pretty much invisible technology in the background.