Just finished it. I loved the novella, and I'm surprised how faithful it was to the source material. A lot of the duologue and scenes were yanked right out of the book.
The lead was very good, as were most of the supporting roles (Ollie in particular). I think the crazy lady was miscast - I could see her as the insane old lady in the book, but something about this one didn't gel. Not sure if it was her age, voice or mannerisms, but I didn't buy her as a scary character the way she was in the book. She went from bit part to preaching phycho too fast; in the book she slowly ramped up to become a threat. Here she starts preaching in her first real scene. And they let her go on far too long.
I liked the creature design a great deal. The details on them were appropriately creepy and mean. The CG, as everyone noted, was terrible (I saw it in color). I hadn't seen CG this bad in a good six years or so (the tentacles in particular). But I forgive that, as it was pretty well used. Monsters galore.
I agree with Stinkles' comment that the film felt rushed. Scenes seem to end a few moments too early, the early character work seemed perfunctory. I wish they spent a touch more time building up the arrival of the mist; the book built a lot of tension and dread by the time it sunk in. Here it feels like ten minutes and we're there. Overall it felt like it was in a bit too much of a hurry.
I also didn't like the film having to spell everything out; what was implied in the book was made explicit here. The cause of the mist, the role of the military, the fate of the wife, the fate of the main characters, the lady that left in the beginning. Leaving
some stuff to the imagination is part of why the book is so haunting. At the end of the day, it
doesn't matter why the mist showed up - it did, and they're pretty much fucked as a result. The book realized this, the movie doesn't.
And yeah, the ending was terrible. That kind of ending can work, but here I thought it was just badly done and didn't fit the movie well. Too much of a "shock" ending. I liked the book's ambiguous conclusion a great deal more. It was haunting. Here it was jarring and oddly comical.
Overall I enjoyed it - mostly good acting, great monsters. The pacing and CG were a bit off, and the ending was poor.