I do NOT know what it does, but I will speculate that it is related to films (on film) that where converted to video in the past using what is called "3:2" pull down which mechanically moved the film in a way that matched the 24 frame per second film speed to 60 interlaced fields which is 30 fps of video, producing a subtle video error called "judder". Wikipedia goes into this at length and does a decent job; look for 3:2 pulldown
So I'll guess the cinemotion tries to back out the judder while also fixing the motion artifacts that are related to interlaced video. 30 years agos Sony and Ampex had competing methods for all this and Sony won, but maybe cinemotion is an 'Ampex corrector". Or maybe it deals with both as neither was perfect in all cases.
In short, probably not a factor for any movie shot in the last 10 years (they shot it on video to begin with) or converted to HD ever (probably converted to 1080p master and then corrupted to 720p or 1080i by the network).
If you watch old movies in SD, it might do something useful, but nothing is going to make that happen on my shinny new 4k... :-)
Edited by jjnbos - 11/22/13 at 5:26am