Development hell is that awful place that no filmmaker or actor wants their movie to end up: it's where a project remains suspended in limbo, unable to move forward with filming, and it can be for a multitude of reasons. Maybe the script just isn't ready yet, or the actors are playing hardball, there are complex legal issues or the filmmakers themselves drag their feet, but these 15 movies, while no doubt highly anticipated, have all the makings of ending up in development hell. Some have release dates whereas others are still just pipe dreams, but each is a dangerous project with numerous question marks which could cause it to never get made. It'd be disappointing for sure in each case, but totally expected at the same time. After all, making even a terrible movie is extremely difficult, and given that most of these movies are long-awaited sequels, the pressure and various moving parts that need to be organised is immense. Hopefully the years will prove this list wrong, but for now, from James Cameron's proposed Avatar sequels to the most anticipated movie in Scorsese's filmography in years and everything in-between, here are 15 announced movies that are surely destined for development hell...