I can appreciate wanting to create (and actually creating) a computer program for this, as well as controller interfaces. I'd do something that was platform agnostic so it would run on any OS (I use Linux). However, for me it would be a fun project, but not something I'd use much past proof of concept. Someone into computers can take great joy in computerizing many things and seeing it work, just for the fun of it.

When the computer is down, however, one hopefully didn't become so used to it that they forgot how to do things manually.

Actually, I have toyed with the idea of automating the exposure and development of 4x6 prints. Sort of an home-made minilab. This would be for quick-and-dirty prints from a roll of film, but not for "good" prints. I'd do those by hand. My idea would also be mostly analog circuitry in case the computer failed, as well as manual over-ride in case the analog circuitry failed. Of course, this is all outside my skill-level in programming at the moment.