Disney doing this is a net good, as it funds more projects. There are plenty of public domain animated shorts and characters, but once out of copyright no one seems to have any desire or incentive to protect or make new works from them as opposed to bundle bad copies of them on dollar dvds.
Disney has lobbied (and succeeded) to have the copyright length extended every time Mickey Mouse is coming up to it's copyright limit. Is it a net good when a multibillion dollar corporation manipulates IP laws to further its own interests? We've had our laws manipulated to protect a cartoon mouse. Copyright was meant to be a short term guarantee that creators could profit from their art, not an eternal claim of ownership.
I don't know about the first part (and frankly I don't care) but my idea of the second part is the same length as a patent: 20 years. 20 years after publication all works irrevocably enter the public domain and are free for everyone to use for all purposes. 20 years after death unpublished works also enter the public domain or are ineligible for copyright. And the law that sets this would state that all existing works now have just 20 years copyright.
