I have been fortunate to work for the last 25 years in the Flatiron District of NYC, which is a mixed-use neighborhood (office, retail, residential) that has excellent mass transit options (three major subway lines converge at Union Square), great biking and walking streets, and a feeling of vitality that is infectious.
So this video I watched this morning rings very true to me. I think cities around the world (both new cities being built in Asia and existing cities looking to transform themselves like Los Angeles) can and will adopt policies that limit sprawl and get us back to living with other people in mixed-use environments that make us happier, more productive, and more sustainable.