Fascinating articles The first article I've run across lately is
this one, which makes some very interesting suggestions about Harry and Hermione's relationship. I don't give all the arguments equal credit, but nonetheless it's well-thought-out and does make some excellent points, including the general way Ron is phased out of a lot of the action, not only in OoTP but also in earlier books.
The second one is courtesy of
Lycoris, and takes the chess match of the first book and applies it to the characters. Lots of good points to be found, and some interesting predictions in the realm of character deaths;
reading it is definitely worth your time.