Well as a format Blu-ray is just a fraction slower than DVD and film.
So the theatrical cut of the Blu-ray is 9 seconds longer than the DVD, despite being the exact same cut.
It's the same for all movies, put in a copy of any movie--even ones that came out same day like when Iron Man 3 comes out. The Blu-ray will be 8 to 10 seconds longer than either the movie in theater or the DVD that comes out the same day.
Er... what ? Really ? That's... retarded.
It's due to the slight difference in frame rate but it's virtually unnoticeable. It's nothing compared to the 4.2% speed up on PAL DVDs which results in a 2 hour movie running 5 minutes shorter.