My wife and I saw this movie today.
I thought it was good. Some excellent character moments, and some great stunts. It actually had a meaningful theme and explored it thoroughly, so that was good too.
Ledger's Joker was very different, of course. Not very funny and not really even over-the-top. I loved his speech to Harvey in the hospital about the "schemers" and how he's just a "dog chasing cars". That was a great scene.
I thought they could have cut it down and streamlined it a bit. There were points where I felt it was too scattered and somewhat random. Some of the mob bank/money stuff wasn't pulled together tightly enough for my taste.
And add me to the list of people who thought Bale's voice was distracting.
Overall: Above average.