My mini-review.

Good news:
It was scary. Good atmosphere and a consistent sense of dread. Good setting with special detail paid to minimize anachronisms. Good effects, everything was visceral and well made. Good acting, especially from Daniel Radcliffe, but consistent with most of the cast. Consistently serious and not made to be ridiculous. Good mystery surrounding the haunting.
Best part:
The fifteen minute long scene in the middle where Daniel Radcliffe spends the first night at the house. Shit gets crazy fast and they pull out all the stops into a fifteen minute long money shot. Creepy dolls, ghost children, muddy footprints, and strange sounds are the biggest elements. Stuff that would make most people run out, even though Dan sticks it out through the whole night.
Bad News:
It's a one man show. If you don't like to see Dan, and a lot of him, don't see it. There are other people, but it's about Dan and the house, not much else. People are quiet while the music is loud. No reason for certain aspects, like the psychic woman. The money shot is done too early, putting the climax in the middle, while nothing ever tops it.
The Worst Part:
The end. As it turns out, the stuff Dan does in this movie to put the Woman to rest don't amount to Shit. He works to help her, and in the end, she kills him and his son with a fucking train. The town's also fucked because she's still killing all the children even though they did everything that should have appeased her.
The moral of the story:
The Woman in Black is an ungrateful bitch. Poor Dan.
Verdict: See it once, either by rental or in theaters, but not twice.