Well, God did warn that he would make it rain for 40 days and 40 nights. Seriously, the Flood may end up being an integral part of Halo 4 or future games. I know we have those here who seem fond of them, wanting a "Flood Infection" game for the future. I really do not understand how that had not been thought of before, at least as far as I know. The Flood was always the last thing I wanted to come in contact with in the campaigns. They could be so unpredictable and the swarming effect never let you have a chance to stop and breath, once they had gotten onto you. Within the campaign, they brought a sense of dread to the game which amplified the sense of hopelessness. I can remember in Halo 2 dropping into, I believe, a control room through a broken observation window above it and having it take maybe 15-20 minutes to clear the room. You would kill the darn things, then some little legged tick thing would scurry over and infest another corpse. I expect there return in the future.