[thezoggy]

Yeah the scanner recognizes a movie subfolder named exactly "extras" (case insensitive) and adds the contained files to the list of extras of the movie (provided you did not change the setting to ignore extras on scan).
They're playable with the extras addon as before, but also through the extras button in the info dialog (new core feature).
Through manage extras you can also add randomly located videos as extras of a movie.

excellent, that is pretty much what i hoped for.