I don't know if anyone took note to the fact that Snape and Harry have something in common. Snape has that Dark Mark that burns him when Voldie calls to his followers; and Harry the scar that warns him of danger. I wonder if this will be expanded upon...?
I dunno. They seem like two completely different things. Harry's warns him of danger, and Snape gets called by him. They may be made by the same person, but they're for two completely different purposes.
I wonder what it was that Snape did to gain Dumbledore's trust again? I hope we find out in the 5th book. Snape is an ever-changing mystery. Gosh, how I love him!