Why does Hollywood insist on ruining the best ideas by casting...*Keanu Reeves*. He was in the Hellblazer movie too...I cannot imagine a worse choice for the character of John Constantine.
Ever since the Matrix he's seen as the "sci fi guy". Granted he was decent in that movie, since his only requirement was to look dumb and say "Woooah", which is the kind of thing he's good at. He needs to go back to Bill and Ted.