My responce to a similar thread on different forum:

IMHO as long as there is demand, V8s and other large displacement cars are here to stay. CAFE only requires the average MPG to be increased while the number of large displacement sport cars are only a small percentage of car sales. Cars such as the WRX/STI, EVO, IS, Mseries, exc are very capible cars that have already taken a large share of the "sport" car market and are already capable of close to 35mpg. In 12 years, they should be able to surpass the set standards by a long shot. Seems like the media is making to much of this story to make the headlines but who knows. (why would they do that anyway ) Only time will tell but I could care less anyway. If i purchase a car with a V8, It will be a classic. Almost everything made today is junk IMO.

Also, the current MPG standard is already 27mpg so this isn't a big change.