There was a good article by Joseph B.
White about why the gasoline engine will be with us for the foreseeable future (lots of power for the pound, low cost). But the Journal also published a table comparing some of the different upcoming greener powertrain options, which had some issues.
I can't reproduce the whole table here easily (but you can read it here). I'll just hit on the parts I think they got wrong.
First, describing Flex Fuel vehicles, WSJ wrote that they have "no price premium" compared to gasoline vehicles. This is not really true, as ethanol capable fuel systems must be made of different materials to resist the corrosive effects of alcohol. Also, the engine control system (mostly the software on the PCM) must be more complex to handle ethanol, because it can be present in any concentration from E10 to E85 due to fuel mixing. This requires substantially more development work by the powertrain engineers, and substantially more testing. The actual cost per vehicle of a flex-fuel system is somewhere closer to $100-200/car, in large volumes.
Regarding plug-in hybrids, WSJ noted that the "advanced batteries are not yet available". This is true, in the high volume commercial sense. However, it was not mentioned that the high capacity batteries required to make plug-in hybrid cars work will be rather expensive, on the order of $3000/car more expensive than the current hybrid batteries.
WSJ got sloppy with pure-electric cars. They wrote, "Technology still unproven. Batteries not available." Except that pure electric cars have been in mass production since about 1900. And batteries are available--until recently, most electric vehicles used lead-acid batteries. The article also misidentified the Chevrolet Volt as a pure electric car, which it is not-it is a "series hybrid", which is a car that has electric drive but can use gasoline to power the electric motor through a generator. What the article was probably trying to get at was that currently, pure electric cars can not compete in range with gasoline cars, but they didn't' say so explicitly.
Finally, regarding clean diesel, WSJ neglected to mention that most implementations require the driver to top off a urea tank to aid in NOX reduction--a definite annoyance, and a minus in my opinion.