EveryMac has posted the exact details of the changes from the "Mid-2007/Santa Rosa" MacBok Pro models to the "Early 2008/Penryn" models. The story notes the new way Apple measures battery life and that the 17-inch models still use CCFL backlighting. In addition, there are changes to the keyboard in the new models.
"Itis also worth noting that Apple changed how the company measures battery life for the iEarly 2008/Penryni models," the article said. "For the iMid-2007/Santa Rosai systems, Apple reported that the 15-Inch models provided 6 hours and the 17-Inch model 5.75 hours of battery life -- with wireless off. For the iEarly 2008/Penryni systems, the company reports that the 15-Inch models provide 5 hours and the 17-Inch model 4.5 hours -- but this is for iwireless productivityi."
EveryMac: One of three comparison charts
Those who are looking for the exact technical differences betwen the low end 15-inch, high end 15-inch and the 17-inch models across the two generations will find this very useful.