From what I've read there is no change to the engine at all.
They just upgraded the intake and exhaust. Something you can do yourself any day of the week. What is impressive is that they have given you more product while lowering the price. That has to be a first in High End sports cars. A new 987 can be purchased for a base sticker of $43K which is only $10K more than I paid for my 2000 S with 10,000 miles. Makes me woner if I should just have bought a 2004. Just kidding
I really really don't like these new lights on the 997 and 987. I would have been very pleased to see Porsche incorporate the Carrera GT lights into the new 911 and Boxsters.