If they can make movies like Saw & Hostel , which are basically movies for people who get off on watching people get mutilated & tortured , then I'll never say "never" to the possibility that tickling and/or tickle-torture can someday play a prominent role in a mainstream movie.
I'm not gonna hold my breath or anything , but forever is a long time. Eventually ... everything comes to pass. It may not be the MAIN theme of a movie , but at some point , I can certainly see a movie that boasts a crazy-long tickle-torture scene ( & by 'longer' I mean more than the 30 seconds to a minute stuff that we may have been lucky enough to get thus far ) or a character within the movie that has a tickling-fetish ... someday becoming a reality.
Look at it this way ... somebody greenlit SuperBabies : Baby Geniuses 2 ( like Baby Geniuses really needed a follow-up ) ... ANYTHING is possible!