Im really disappointed by the spec so far, I would much prefer there to be a fuel tank size limit only and no fuel flow restriction so we can have wacky qually engines like the 80's and decent RPM's (14,000 RPM for the bore/stroke specs is easily reliable with current engine tech).
KERS is a green elephant and im not impressed by it, if F1 wants to be green and relevant to the future it should introduce additional engine classes like an all electric drive-train class with hydrogen fuel cells or other electric storage systems as well.
All electric is prolly not a 100% competitive tech for a while but genuinely useful for the future - heck they could give the electric classes "re-fueling rights" to swap out spent fuel cells while not allowing the ICE class to refuel mid race.
Big Car Companies could pair up with the back marker teams and use them as alternative tech test beds until the tech is strong enuf to compete at the top level, this would help them stay viable and make things quite interesting imo