The writer doesn't have a sweeping vision for a third season. Just a general idea. He believes if the fans want one, there should be a third season, but he has no power in that department. I can't imagine Chiaki J. Konaka is tripping over his feet to getting back to work on the Big O either. His influence is clear, but I doubt he considers it his finest work.
Still I would take his best guess over Cartoon Network's current ideas for Adult Swim programming. "Perfect Hair Forever"?!? That's one of William Street's "big ideas"? *smashes face on keyboard*