W. T. F.
Okay, Disney has long been famous for making movies that have virtually nothing in common with their source material (I first noticed it personally in 1962 with Big Red, a movie that shared with the novel (a) an Irish setter and (b) Canada. Period. Other "favorites" include Bedknob and Broomsticks, The Jungle Book (animated or live action), and The Ugly Dachsund ... but nothing, nothing, can top this.
Jennifer Garner as Miss Marple.
And before you say "Hey! You liked Sherlock, you hypocrite", let me point out that precisely one thing changed there: the time-period. Nothing else. Garner's Marple won't just be a 21st-century Marple, she'll be a 38-year-old American 21st-century Marple. And I'm betting she'll end up with a man by the end of the movie...
But I won't be watching it.