As you've noted, the vast majority of films are shot at 24fps, with some early films at 12 and 16fps and HD IMAX at 48fps. A display that can accept and show a 24fps progesssively scanned 1080p24 input at full spatial will avoid a range of potential artifacts, and if well engineered should give an excellent picture with blu-ray. Converting film-derived material to non-integer multiples of the basic 24fps introduces significant artefacts which are likely to be even more obvious at the higher spatial resolution of HD (compared to SD). It is likely that material will be shot at 48, 72 and even 96fps in the future, to give a more realistic and fluid sense of motion.
A normal TV can't even accept 1080p resolution, so for that the 24fps question is academic. CRTs and similar displays would flicker dreadfully if scanned at 24fps, and even displaying each frame twice to give 48fps would have significant flicker. 72, 96 or even 120fps would be more satisfactory, and it may even be possible to have a mode where the in-between frames are estimated and generated onboard in realtime, until true high framerate 1080p material becomes available.
