The new Harry Potter movie starts off with a stunning open sequence but then meanders all over the place with no real plot coherence. Even the opening sequence, which shows Death Eaters attacking London, has no apparent relevance to the rest of the movie and is never mentioned again. That’s what I mean by no plot coherence.
As for the Half-Blood Prince, you finally do get to know who he is, but just barely. Sue, who has read all the books, says the Half-Blood Prince is explained much better in the book – as is most everything else. The book was exciting, and the dialogue was already good, she says. So why did they change it? And produce this uninspired mish-mash instead.
The whole thing just seems a build up for the final movie, where we’ll see the final battle between Harry and Voldemort. At least that might be exciting.