You're the 2nd person I've heard say this, I'm a little perplexed as the movies are effectively the same one from the PS3, except in MP4 instead of BINK format (makes them smaller, but with much better quality).
The movies are created from the original "frames" that OWI rendered off for the Xbox version back in the day, which are all 720x408 tif files.
The problem might be that we are upscaling them to 960x544 from the 720x408 16:9 mp4 files at runtime.
The PS3 version upscaled from 720x408 to 1280x720 but had MLAA on them, so it could be something as simple as the missing MLAA on them that gives that impression, but the really better versions a lot less artifacting for movies that are a 1/4 of the size of the original BINK files.