Umm, isn\'t HD broadcast run faster than 24 frames per second?
I believe it runs at 60 frames per second progressively in 1280 x 720p resolution with 4:2:0 Y:U:V sampling (color sampling equivalent to 12 bits RGB bandwidth).
Actually there are two popular HD formats for now:
1080i and 720p. Both have a faster frame rate than 24fps.
1920 x 1080i is interlaced and runs at 60 fields or 30 frames per second.
Only movie runs in 24 fps usually film based like 35mm. Why? Well of course, to cut cost. To think movie studios spending multi million dollars on a movie, they would have speed up the camera speed to 30fps or higher. But, they still use 24 frames per second and spend the money elsewhere like to themselves or to the filthy rich casts.