I ran across a review before I went to see the movie, which said, "No character, no matter how well established in Batman's history, is safe." Hell, I thought they were going to kill Alfred. When I read that, plus many reviews that mentioned the death of a "major character" (I figured everyone already knew Rachel was going to be Joker fodder so I kind of discounted her death), I was pretty ready to be fooled.
Good ol' hype. My negative reaction to Ledger, the tone & the overall film is somewhat in response to how awesome, different, dark Newsweek and Time claimed they were. In addition to seeming derivative, Ledger seemed too young, punkish. For "having no agenda", he was initially too closely affiliated with the mob, and he was too bad all the time, rarely amusing, and so not too interesting (I did like his second explanation for the scars).
We get a great character study on what it means to be a hero
It seemed too simple to me, Bats losing heart easily & not explaining himself well, not seeming to have a lot of inner conflict about the violence, certainly not about his methods.