I live near a place that is pretty close to what you describe. I live in a townhouse within walking distance of a miniature "urban downtown" type area. This miniature downtown is close to a rail line to the city.
This whole area was developed more or less from scratch over the last 15 years. The end result has been pretty nice, and it's become a pleasant and desirable place. I do love it, and I think if more people tried this style of living they'd find it's a nice mix of the pluses of the suburbs and the city.
The downside is that it's NOT affordable. Now that the place is nice and pleasant, housing in this area is starting to be priced at a steep premium - well above average. I expect that to get worse as long as this area is successful.