The logline: "A group of people are trapped in an elevator, and one of them is the devil."
Right off the bat I should say that I have an almost irrational affection for movies that take Satan seriously as a walking, talking character. (As opposed to a tormenting spirit a la The Exorcist, which is also cool, but a whole different animal.) When The Devil's Advocate came out, I was obsessed with it for months. And I always find myself willing to tolerate a lot of crap from movies like End of Days for the same reason. My biases also include a love for claustrophobic little thrillers with a psychological bent. (This one almost sounds like something dreamed up by David Mamet.) And have I mentioned that getting stuck in an elevator is a long-standing phobia of mine?
I'm also a Shyamalan apologist, and his involvement in this isn't surprising: like all of his films, Devil is conceptually brilliant. It's the execution that's in question. The linked Slashfilm post reveals a few more details, none of them as interesting as that ridiculously beguiling conceit, which might be a bad sign.
Oh, and pop quiz: given what you know about Shyamalan's propensity for twist endings, and his approach to faith and spirituality, any guesses as to who else might be in that elevator?