24p is a big deal for the Yanks because their TV is in 60i right now, which deinterlaces down to 30p. Film is shot in 24p and so the cousins don't like the video-like effect they get if they watch movies encoded for TV at 60i.
In the UK we have PAL (cheer, let's hear it for PAL), which is broadcast (TV) at 50i. This deinterlaces to 25p.
I expect that there will be those who imagine they will be able to see a difference between 25p and 24p but I don't claim to be one of them.