To my knowledge it doesn't let you go in the other direction with motion interpolation though. Maybe there is a way to get blender to run a video through ffmpeg's minterpolate filter, but I haven't looked into that.

late edit: if any Blender developers are by chance reading this, my greatest gripe with Blender is that it doesn't use ffmpeg for encoding, making it infeasible to leverage ffmpeg's many desirable features and supported output codecs and formats (at least not without the inefficiency of going through a lossless format. ick!)

Ah yes there's that weird design where there's a "movie clip editor" that is a totally different tool from the sequence editor. Why can't I import a clip into the sequence and then edit it? Very confusing.