well...
I think public transportation is very valid in areas where population density can support it. Europe is better suited to such infrastructure because it was originally built around the village.
On the contrary, large sections of the US were populated after the car became widely available. It's unlikely that great swaths of the existing populace can practically rely on a public transportation system. It's all well and good to talk about bicycles and light rail, another thing to completely remold a society that was predicated on the personal automobile.
Along certain major routes, rail is great, but off those routes, it becomes increasingly impractical to build and support fixed routes. Buses running on fuel cells, or something of this nature, would be a more flexible option that would easily take advantage of the existing roads, but even there, you'd be talking about such sporadic or limited riderships that funding those routes would rely heavily on subsidies.
The simple fact is, the world is not going to give up the automobile overnight. The economy is built around it in many sectors, you can't just ditch it without a lot of planning ahead. The shifting to a post-carbon world is going to be a gradual one... it's not going to be easy, and chaotic, violent disruptions to the society need to be mitigated.
If gasoline became unavailable overnight, and cars rendered useless, you'd have anarchy, riots, deprivations on a mass scale. The automobile will be with us for a while, and so practical solutions to making it cleaner make perfect sense. Think of this technology as one that bridges where we are now and where we need to go, not as a delaying tactic.
I think most everyone can agree that an electric vehicle is better than a fuel-burning vehicle, and an electric vehicle with a 40 mile range is better than one with a 25 mile rage- it is progress.
There are many other things to consider, including environmental (bitter cold, snowy places aren't great for biking in, and mass use of sled dogs ain't gonna happen!), the swelling ranks of the elderly (can you imagine forcing granny to hobble everywhere?), even the huge losses of jobs that would follow the death of the auto.
No, like most everything else, it's not an all or nothing proposition. It's a patchwork of slow, practical steps towards our more sustainable world.
And let's face it... much of our problems today are the result of the population explosion. As simply wishing, or unthinkably, 'removing' this problem away quickly isn't an option, and as all these people tend to want to live at a certain comfort level...well, it's not really possible to halt that as long as there's someone willing to provide it. As long as it's profitable to provide it, it'll continue. Improving economy and ecologic standards, therefore, can only be a good thing, if not a 'perfect' solution.
I'm all for whatever takes us closer to cleaner energy. A Volt charged up with windpower and kept within it's 40 mile daily range would be a VAST improvement over an SUV getting its fuel from a convoy in Iraq or an offshore oil well.