However! I've been re-reading POA lately and something caught my eye. During the chapter "Gryffindor versus Ravenclaw" Harry has a dream and it sounds really similar to when he is chasing Snape's Patronus through the Forrest of Dean:
"He had a very strange dream. He was walking through a forest, his Firebolt over his shoulder, following something silvery white. It was winding it's way through the trees ahead, and he could only catch glimpses of it between the leaves. Anxious to catch up with it, he sped up, but as he moved faster, so did his quarry. Harry broke into a run and ahead, he heard hooves gathering speed. Now he turned a corner into a clearing and -"
Come on people!? Sound a bit familar?!