It'd be pretty cool if we could make this an option. (of course only high-end computers could probably run the osu mapping + 60fps video in 1080p at a good fps)
Er.. Right.. osu! isn't youtube that limits the video playback in a set framerate imo (though yt slowly climbing to 60fps playback). It depends on the video on how it is rendered by the fps. You can map and play osu! on 1080p if that's what you're asking.
I've been experimenting with different video encodes and I've learned that if you want osu to play 60fps video correctly, you have to use a flv file type with flv codec.