I do have hope for Snape. Remember the argument that Hagrid overheard Snape and Dumbledore having? It was never resolved what that argument was about. I think Dumbledore was telling Snape that he ~had~ to fulfill the Unbreakable Oath. I think Dumbledore knew, and when he was begging Snape at the end, he was actually begging him to ~do what had to be done~.

That's my 2 cents. And honestly? I'd be pretty upset if Snape was just "Irreversibly evil."

And four days isn't slow at all. It's actually pretty fast.

I have no clue how long until book 7. Sorry.