Oooh...But, why did he not harm Harry when he was escaping Hogwarts.? I remember reading that and thinking how strange it was. He has always hated Harry, always wanted Harry to suffer, but DD would never allow that. So why, with DD gone and Snape's position with the DEs out in the open, why did Snape refrain from hurting Harry? He had the perfect opportunity to exact revenge on Harry. No one but Harry was following him. It would have been so easy. I haven't heard any theories on that one yet. I used this fact from the very beginning to defend Snape, vile as he may be. I cannot believe that if he was really bad, that he wouldn't, at the very least, have put the Cruciatus curse on Harry after he was found out. He'd have nothing to lose. Harry is running after him, trying to hurt him as much as possible, and all Snape does is deflect the curses. It doesn't make sense and only works if Snape is still really on the Order's side. All that hatred he has felt; he could have hurt Harry and enjoyed evry second of it.
I think he is awful, but that he is still trying to help in the fight afainst Voldemort.