Ianqui, you may be a little premature, even naive.

  1. Remember, some years ago, a little itsy bitsy seven cent gas tax helped sweep Newt Gingrigh into power in the Senate? Folks are worried about the price of gas. They're not looking for it to be raised further; they're not looking for social transformation. They just want the price down. Which is why they want price controls, which will create the mischief econbrowser.com suggests.

  2. Rezone for mixed use? Fuhgeddaboudit. Folks have been taught for years that absolutely uniform isolated single-use pods are essential keys to the Eternal Free Ride From Ever-Escalating Property Values. I dare you to try to get rezoning for use of any exterior paint that's not the exact shade of Homeowner-Association-Approved shade of Theme Park Earth Tone Beige. Put a store anywhere near me? Are you nuts?

  3. New developments or towns? Maybe. Some of that has been tried in my area, which is a university city. But there's a serious transitional problem. The businesses can't, and don't, survive. Unless you build or transform a really large area, the businesses have to live in the real world, which means they need parking. Alas, "smart" or "new urbanist" development is a theme park too, and adequate parking for the businesses to survive doesn't fit in.

It can be really difficult to transform society based on Grand Plans.
The idea that we should all be living in gated communities with isolated commercial zones 10 miles away is a learned behavior. With a good PR campaign, people could also begin to learn that having access to amenities is desirable.

There are different kinds of people in this world. I live in Manhattan with shops all around me. People pay astronomical rent to live here so they can participate in this kind of lifestyle. Other people like to live in older-but-Smart-Growth-esque towns like Tenafly, NJ or some of the older Boston suburbs that have town centers with movie theaters, boutiques, coffee shops, and ice cream shops. Homes in these places are also expensive, presumably because people want to live there. So not only is the Smart Growth idea not new, but there are plenty of people in the U.S. who are desperate to live in just that environment. It's not a lost cause.

with $3 gas, people might be more willing to consider the efficacy of living near retailers - just not Walmart-esque big box retailers. Ithaca, NY (my touchstone for these sort of things) fought hard against a Walmart and kept its downtown district intact through the 1990s. Even the large supermarkets (I live Wegmans) are within 2 miles of downtown and require only a very short car ride to get groceries - for those without cars, they deliver for a nominal charge.
I agree, but there is a hell of a lot to unlearn.  Let me give you just one example:

When I was a kid, we still had the corner grocery store, and this was before the 7-11-ification of the small grocery stores.  Sure it cost a little more, but if all you needed was a loaf of bread or a can of soup, I could just hop on my bike and pick one up without anyone needing to get in a car.  Heck, it was even walking distance.

In some neighborhoods, you still see the houses that used to be the corner grocery.  The front door is on the corner of the house instead of the middle of one of the sides.

I have to admit though that even the large grocery stores have become 7-11-ified.  Entire aisles filled with potato chips.  The next aisle over is filled with sodas.  The next one over is a freezer case filled with frozen snacks and pre-made dinners.  It is pretty damn clear that not many people even make an attempt to cook any more.  Even the Asian market that I shop at has aisles filled with various jars of pre-made sauces, or bags of quick frozen dumplings - it still seems better than a regular grocery store.

For all of those folks who cannot even be bothered to pick up a quick-frozen dinner of some kind, there is always the drive through - even crappier fast food, and burning even more fuel in the process.  If that doesn't work then order a pizza and they deliver it to your home.

You could argue that people don't have the time any more to cook a proper meal, and to an extent it is true.  These days you have both parents working, so if you are coming home tired it is easier to pick up some take-out rather than go to work in front of a stove.

Now take this and multiply it by 10.  Virtually everything we buy these days involve getting in a car and going someplace.  Heck, virtually everything people think they need to do involves getting in a car and going someplace.

"Alas, 'smart' or 'new urbanist' development is a theme park too, and adequate parking for the businesses to survive doesn't fit in."

I dispute that. I've evaluated hundreds of new urbanist plans, and sat in on several charrettes (week-long design/planning sessions). New urbanist designers are terrifically concerned with parking in their designs -- I've even heard the mantra, "parking is destiny." The best policy for parking is to base its cost and supply on market demand whenever possible. The bible of parking reform is Donald Shoup's book, "The High Cost of Free Parking."

New urbanist town centers have proven very popular and profitable for developers; those are some of the reasons why the Urban Land Institute offers seminars, books and guides on the subject. Also, the leading industry organizations, ULI,  NAHB and NAR, have each adopted smart growth as a focus area.