In a recent interview with HitFix, Severus Snape actor Alan Rickman gave some clarification to the myth that author JK Rowling told about him the fate of his mysterious character before anyone else knew. From the article:

Before I could even finish my question about this anecdote Rickman jumped in to clarify.

“Not true. I don’t know who thinks that is true, but it’s not true,” Rickman says. “She gave me one tiny, little, left of field piece of information that helped me think that he was more complicated and that the story was not going to be as straight down the line as everybody thought.  If you remember when I did the first film she’d only written three or four books, so nobody knew where it was really going except her.  And its was important for her that I know something, but she only gave me a tiny piece of information which helped me think it was a more ambiguous route.”

So, in many ways, Rickman’s portrayal through the series is even more impressive as he had just one nugget to use as he shaped Snape over the years.

Rickman adds, “What I knew was he was a human being and not an automaton and I knew there was some sense of protection for Harry or I worked that out. It was enough to know, I didn’t know he was a double agent.”

You can read even more great stuff from Rickman in that article at this link.