Well as a format Blu-ray is just a fraction slower than DVD and film.
As others have said, this is not correct. Almost every Blu-ray runs at 1080p/23.976 frames per second, which works out to the same speed and time as NTSC DVDs, which are natively 480i/59.94 fields per second.
However, it is true that a 23.976p Blu-ray and 59.94i DVD will be slightly faster
than a film running at true 24.00p (or the occasional 24.00p Blu-ray).
I'm in a PAL region so it's difficult for me to check the running time difference between blu-ray and NTSC DVD. The only one I've been able to check is The Avengers which I imported from the US and there is a 6 second difference in the running time. I also tried converting some 23.976 videos to NTSC DVD and it reduces their running time by a several seconds. I'm guessing it's a side effect of NTSC display timings or 3:2 pulldown being added to the video.
I believe this is because some DVD players or software video players use a "drop frame" formula to calculate the timecode and running time, while others use "non-drop frame." This results in a difference of about 3.59 seconds per hour.