Unfortunately this doesn't change the manufacturers' required average fuel economy across their entire fleet (CAFE standards since that calculation is measured differently than what the EPA uses to put on the window sticker. EVERY car's fuel economy will go down, but this in no way is going to lead to a rise in fuel economy standards -- it's just appearances.
Also, does anyone else think it a bit silly that manufacturers advertise subcompacts as fuel efficient when they get an average of 30+ mpg (pre-EPA change)? Whereas in Europe cars AVERAGE 33 mpg? Manufacturers say that people don't want little fuel efficient cars over gas guzzling sedans, but honestly when the difference in economy is 30 mpg vs. 25 mpg it makes no difference!
Just a thought: it seems to me that many people who would likely buy a small, gas sipping car are the same cheapos (like me) who would keep their current car as long as they can. So they tend to buy fewer cars (and therefore fewer fuel-efficient cars) in general. Whereas the folks who don't care for gas mileage may buy gas guzzling cars more frequently...
And a gripe: Why do people keep using any dollar figure less than $3.00 for fuel estimates in comparing the recovery costs of hybrids? Gas prices have tripled in the past 8 years -- what makes people think that we will pay $2.60/gal for gas over the next 10 years? Take the bus! Tell your kids to bike to soccer practice! That's what I did as a kid, uphill both ways.