Something that is interesting to notice is that it seems that movie ideas can come in cycles. Some cycles last longer than others, but they do not last forever. This concept stems from the fact that it seems that over certain time periods you will see almost the exact same concept show up in a bunch of different movies from different studios. Often you will see one or two that stand out and then the others will have fallen flat. Depending on how well the good ones do the cycle might last years or just a year.
Part of what happens during these cycles is that after watching the trailers it feels like it is all various levels of the same movie. Why do some of these cycles last longer than others? Why do the cycles seem to happen in the first place?