Out of curiosity: If you were writing a new copyright statute to cover software, how long would you make the duration of copyright?
Five, with the ability to extend with five more if registered and source code placed in escrow for the public upon expiration.
Interesting question the way you worded it - "a new copyright statute to cover software." I read it to mean the same scheme as now, which is same term for all types of works. To that, I would say between 30 years and life of the author, but not longer. I do believe that an author of a work should get all the income from the work as long as it's at a commercial level of income production. So you get to earn the fruits of your labor but your kids are on their own. Part of this might be to protect moral rights too, so that an artist doesn't have to witness the mutilation of their work.
Software is a different thing, though. It's continuously improved (so you don't want to protect against "mutilation") and has a shorter commercial lifespan which would suggest a much shorter term of protection. Five seems short to me, but I don't really know. I probably would have said 10.
Pam