Will it terrify little children? I would have thought so, but we read this to Tristan all the time and he's 2 1/2 and has no qualms about it. I suppose if nobody has ever told you monsters are scary, you have nothing to fear.
The film is being directed by Spike Jonze and adapted by Dave Eggers, so the material is in good hands, but I never thought we'd see this on the big screen, let alone a live action version.
Here's a bit of leaked footage:
(Poster via ComingSoon)