I have seen some of this stuff discussed in the book "Superbia!"

The only thing is, this is an incredibly expensive proposition. Not all suburbs [[and especially not all exurbs) will be suitable for this retrofit. Some areas will have to return to productive farmland, recreational purposes, or simply greenbelting.

I worry that we could focus too much on the argument, "Oh, we'll just retrofit suburbia for the 21st century!" and ignore the idea of investing in an actual city center. It's good stuff and I like it, I just worry about it being misinterpreted and misapplied.