So I saw Harry Potter twice this weekend, and I really liked it. The only parts that I didn't like were parts of the story that got changed due to liberties taken by previous filmmakers. If the 5th and 6th movies had been made properly (especially the 5th) then this movie would have been ten times better. But it didn't suck, by any stretch of the imagination.
I know some of the critics are blasting it because the movie just ends abruptly without any kind of climax or conclusion, but I only have one question for them: What part of "Part 1" don't you get? This is roughly half of the story. A story written into a single book that's been split into two movies. What else could you expect? No one complained when Pirates of the Caribbean did it with the second and third movies (and they REALLY should have because it was bad writing). And no one complained when they did it with the Matrix (okay, maybe everyone complained about the "sequels" to that epic film). All that to say: it was a great movie that the critics can just stop whining about.
If you like Harry Potter, go see it. It was awesome.