If we assume that technology and communications is improving, and the pace of progress is increasing then logically the duration of monopoly should get shorter and shorter rather than longer.
Nowadays if a movie is good it makes a profit within a few weeks of its release. If it's not good, stop making bad movies then.
It is ridiculous that there should be a monopoly for > 100 years.
Think about it, if copyright only lasted 7 years, do you think Microsoft would dare release something as crap as Vista? They'd have to make something significantly better than Windows 2000.
If Microsoft won't want to play by those rules, I'm sure Apple or some others will be happy to take over.
As for patents and people talking about drugs needing long patent terms, the AFAIK drug companies spend more money on marketing (aka bribing doctors with goodies and holidays) than R&D, and FDA approval.