Uh-oh! I like your theory!!!

I really think as you do that Snape killed Dumbledore because he told him to do so...

I also think that Sirius should be back because that kind of death was a 'no, no' in my book...

and what you say makes sense... I have always thought that Neville would have an important part later and still haven't come the time... He has helped here and there but nothing too spectacular...

if you're right, it will be pretty cool... but knowing JK Rowlings... who knows... It's hard to decide, if she wants to kill to main characters that would they be: Harry and Ron, Harry and Hermione, Hermione and Ron... I especially like Hermione, so I just hope she doesn't decide to kill her :S

Now we just have to wait *sigh*