Just watched the movie and I can say that...
SPOILERS ***** SPOILERS ***** SPOILERS
I can say that THE DARKEST HOUR is fairly entertaining. I go to science fiction movies at the theater to be 'entertained', not to see some philosophical, artsy, mind-numbing, talkie drama. If I walk out of a sci fi movie afterwards feeling entertained then to me the movie was successful. Like most sci-fi flicks, I don't need blood and gore; after all, that's the horror genre. Blood and gore should be kept to a minimum in science fiction; less is more.
However, I don't think the movie, as entertaining as it adequately was to me, was worth the stunning $12 I had to pay. I didn't even know the ticket price had risen since the last movie I'd seen at the same theater one month ago. And this was not the 3D version, which would have cost four dollars more. Since the movie was just a fair sci-fi flick to me, I felt cheated by the high ticket price.
THE DARKEST HOUR would have been a very good, direct-to-dvd movie or a high-quality sci-fi channel flick.
I like the sense of suspense in the movie, almost reminiscent of, "The Vanishing on 7th Street". Bear in mind that THE DARKEST HOUR is a sci-fi movie, not a horror flick. What I appreciated as well is that a deserted foreign city like Moscow can convey the same eerie sense of foreboding, dread, and scary isolation, just like Los Angeles in a similar apocalyptic sci-fi movie. When all the people are gone, a city loses its ethnic and national identity and just becomes, well, a large, empty urban center.
My judgment: Wait till this movie comes out in the rental store and then definitely go rent it.