I just finished watching the Borders-sponsored "Great Snape Debate" film from the Phoenix Rising conference in New Orleans this May. It's brilliant; I can't recommend it more highly. Wow.
Here are the topics the panel considered:
Chapter 1: Panel Introductions
Chapter 2: Harry as a Witness
Chapter 3: Snape: More Interesting as Friend or Foe?
Chapter 4: Snape: Black, White, or Morally Gray?
Chapter 5: Snape and the Unbreakable Vow
Chapter 6: Snape and the Unbreakable Vow II
Chapter 7: The Motivations of Snape
Chapter 8: Lucky Potion/Greasy Kid Syndrome
Chapter 9: Snape Loving Lily?
Chapter 10: A Mother's Love
Chapter 11: The Unbreakable Vow Theory