What race was Sauron?
What has he looked like, before he made the one ring?
Was he evil from the beginning, or had something happened to cause him to turn to evil?
Is he dead, because destroying the one ring is the same as killing him?
Should Middle-Earth expect Sauron's boss, or a Sauron worshiping cult, or an insane follower of Sauron to turn up in the fourth age, and attempt another Middle-Earth domination plan?