The proper course of action to take on Copyright Law is not to fiddle with the length of protection, but the manner of it. I do agree that Life + 70 is way, way too long, however dropping it to 14 is also very problematic. A properly effective system would protect the rights of the author while still giving access to the work to the public domain within a reasonable time frame. Specifically, I believe the best solution is to give different time frames for different aspects of copyright.

The author should maintain full control over the actual work he or she created for a significant period of time, perhaps something like Life or 50 years, whichever is longer (to provide benefits to the author's heirs in the event of an early death). However, the right to create derivative works should become available to the public after a much shorter period. 14 years sounds good to me on that one. This will allow innovation and elaboration to continue without removing the author's ability to profit from his actual creation. Combine this with a statutorily strengthened Fair Use doctrine and you have the beginnings of a legitimately fair system.