James Cameron has earned the right to take his time to develop these Avatar sequels. Much of the problem of blockbusters is that they simply don't have enough time in all facets of production. Release dates are set before any development of the films are done. It's why I hope the Avatar sequels will be even better than the first one (which I like but don't love the way I love some of Cameron's other films) because he's taken 10 years to get them ready.