In 2008, the EPA changed it's mpg rating methods to account for faster speeds and acceleration, A/C use, and colder temperatures. This resulted in the lowering of the mpg ratings for all cars (and particularly for hybrids). (See video on the subject:
2008 Fuel Economy Tests )
For the 26 years I've been driving, I've always regularly beaten the EPA estimates for every car I've owned long before I ever heard of hypermiling or ecomodding...just using common-sense driving.
For me, the new numbers are less informative rather than more. Now when I look at the mpg numbers in a new-car ad, my brain instantly goes into "ignore mode".