Just finished book VI, in anticipation of the finale. (Gave up on reading the french versions for the last few).
Kept on getting caught up (as has been mentioned in all the reviews) how much Rowling draws from all the fantasy epics in popular culture. The Dark Side/Voldemart/Sauron uses fear/anger/hate while Luke/Harry/Frodo's advantage is friendship/love/pity, as we learn from Yoda/Dumbledore/Gandalf. And yet, while Luke/Frodo/Harry's advantage is his friends (Han/Leia, Sam/Fellowship, Hermonine/Ron), he must in the end, go it alone, abandoned even by his mentor as Gandalf/Dumbledore/Yoda dies, to complete the hero cycle.
I guess there are deeper meditations on the nature of good and evil here. Universal truths. Either that, or epic authors have been following the same cliches for thousands of years.
Anyway, on to book VII.