The great thing about the Super 8 Cartridge system, compared to the old Standard 8 system with film on a spool, is that you can get away with opening the camera up and are only likely to fog a few frames. If the film in the camera has been used up then yes it may be possible to have it processed. The only issue you may find is that back when I shot cine the most common 8mm stock that you would find was Kodachrome 40. Unfortunately it is now not possible to get Kodachrome developed. The process used chemicals that it is now not possible to use from an environmental protection position. If it's a Fuji, or Ektachrome film you should be OK as they are E6 process.
Also remember that the 8mm film frame is very small, and so quality is very low too. Also most 8mm cameras could shoot at 9, 18, or 24 fps IIRC, at least here in the UK. It was probably most common to shoot at 18 fps, since that would you give you about 3 minutes of cine from the standard 50' roll/cartridge of film.
Oh and if it is a sound capable camera it is good to know that the audio track is recorded on a magnetic stripe, but that the sound record head is about 2" past the film gate, so although the sound is synced to the picture, you cannot cut the film, to edit it, without having to lift the audio and edit that, and then re-record it onto the final cut. Of course if you are going to get it digitised that won't be an issue, as you can at least edit it in your video editor.
IMO a twenty year old mobile phone shooting VGA video is going to be better quality than your average 8mm cine output. Still it's fun to play with. If you want to have a play I'd go the whole hog and keep the whole process analogue. You can pick up projectors pretty cheap, and splicing film is real easy once you learn how.
Alan
