Here, let me take a moment to introduce my mother whom also agreed with this idea. (Those who know me will know that without my mother, this Snappish Lady Claudia wouldn't be so cheerful and happy in life and so I'd like to introduce you to my mother now.)That was also my mother's opinion that it was way too obvious. "Why make him the pseudo-evil character from the start and then let him run away with murdering Dumbledore since it was expected from the very start?!" That's what she told me when I was almost crying because of what Rowling made Severus do, and I think she's right as usual. She even thinks he may come back as the hero whom everybody doubted but who will finally get the recognition he deserves in the next book. Let's hope she is right once again!
So indeed, this Snappish me has a mother and she cares about me lots even though I'm like that. She's my very own private Dumbledore. I swear, you would be surprised how much of a Muggle-Dumbledore figure she makes. A shame we won't get to know how she'll be at 150! Ha ha! She was born in 1956, so she'll be 50 in half a year. When she asks: "Why do I almost always get it right when it comes to people's feelings and such?" or "Why are people afraid to speak to me and call me 'special'?" I just answer that is because she's a 'Dumbledore' and that people fear having their true self uncovered by the 'old man' ^_^ Before the HP books, I used to say Yoda because she has always been, as long as I lived, the Yoda-master type even though that's never been her goal. We said Yoda because she will often say spiritual (not religious!!) maxims meant to help you, she invents them as she goes and they're always full of common sense, love and truth. So true it even hurts! She does not have the eloquence of preachers or politicians, but when she talks, people listen and do what she says because what she says makes so much sense all the time. When I was a teenager, it was so unnerving! But even so she kept doing what was right and it didn't took me long to go back to her and apologize. She goes the extra mile, she will find that very reason within the darkest of your heart that keeps you from doing something. She'll see that part you're trying to hide, very little people escaped her 'inner-eye'. Ha ha! She will talk in a non-directive way while conversing with you, but then she will be direct at the same time using frank words, no pleonasm there!! Oh no! That's why lots of people run for cover ; ) She's so good at understanding people's feelings, relating to them, do her best depending on her values, reevaluate herself all the time with much introspection, and she even has that (hum... how can I say?!) 'energetic and attractive aura' about her that makes everyone turn their heads when she goes somewhere. And even though she's shy in public, she'll still be herself and attract much (unwanted) attention. She's got such a brilliant and 'white' energy or light that people trust her. 'Evil' people do not of course, but even with those, she will not condemn and she'll forgive. It's really hard to explain, but trust me when I say she's her very own Dumbledore. And yes, she's wacko-like at times like Dumbledore and sounds pretty naive, too, but she's genuine and very funny. No lemon-sherbet for her though ; ) And just like Dumbledore, she's a lonely person because not a lot of people can take staying with her for long because of that emotional intensity and constant search for the truth. A shame Dumbledore is too lonely, it surely is the cause of his mistakes. That is why I love fan-fictions where Albus serves as an emotional guide to Severus, I know just how it feels to be guided and loved by such a wonderful intense person. I also know what it's like to disagree though! ^o^ She's not exactly like Dumbledore, no, but she's that type of person anyway.
As such, she's very good at guessing the end of such sly novels or movies if you know what I mean. That's why I'll cross my fingers that she is right once again for Book7. Or else, as she said, Rowling would need to be taken down a peg or two for her plotting skills and the way she condemns some people.
Therefore, I agree with Paul and Samantha that Snape is too complex a character to fall down like that and it's way too predictable for JKR to kill Dumbledore using the one character we've doubted since the first book (not us, I mean the general readership of the HP books), unless she's decided to surprise us by being obvious this time. That would be the epitome of wickedness from her