I'm a "current" user on Movies & TV SE Site, yet relatively new to SciFi & Fantasy. I see a lot of questions here which would and could be more easily answered over there, such as "ID this movie" type questions. I'm curious why these types of questions aren't directed to that site from here more often ... in fact, I don't remember too many ever being redirected from here. I realize there is a huge segment of the movie industry which is dedicated to SciFi & Fantasy, which would make for a corresponding overlap. These questions are on-topic here, but would make a LOT more sense being there. I'm just wondering the reasoning or why it isn't more prevalent to move them.
Given that there's just as good a case to be made that all SF-related questions on Movies:SE should be migrated here, the consensus (for the time being) seems to be to let sleeping dogs lie, at least until Movies:SE comes out of beta and we start looking at formal migration paths.
As has been discussed (at, considerable, length), since we have both a Movies:SE and a Science-Fiction:SE site, it's best left down to the individual user to decide which would be most likely to provide the best response to their question.