I used late FP on Christmas Eve at RSR. When the cast member saw they were 7 or 8 hours late, she warned us that starting next week they would be enforcing the FP return time.
She didn't say if this was just for RSR or if it was everywhere you can use FP.
I think she was just spreading the same rumor that's been going around. Of corse next week is 2013, so maybe they are going to start enforcing in 2013.
I sure hope not. I hated FP until I learned I could return when it was convenient, now I love FP.