To me, this plot had quite a nice touch, yet it seems they did not really think of an exit strategy. It could basically end the Green Lantern thing for good, or at least render all of Johns' plot points useless. Reminds me of the Spider-Man secret identity revelation. From this point on (everyone targeting the Parkers) there was not much room left to explore. So there was no other joice but to revoke the whole thing. If the energy drain stuff gets thrown out of story, it makes the better part of 2 years of storytelling obsolete. To me this makes the difference between good and mediocre storytelling: either you can add something to the whole myth (or expand it / put a new twist to it like Johns) or you tell a story which will never be mentioned again 2-3 years from now because it was revoked from the get-go.