best way to get it released would to be pass anti-copyright laws on media companies that sit on and refuse to release art.
If they refuse to let people see it officially, people should lawfully be allowed to distrubute it and the media becomes public domain.
That way even if its on naff DVDs, most stuff will see light on DVD.
Of course that opens a whole can of worms, but I can't stand people wasting art. It totally defeats the purpose of making it, I can't see any point in sitting on something in this way. However, if there was a time limit set, which when expired they have effectively waved all rights of owenship if they don't make it available, then we'd see a whole wealth of material available as its meant to be.
Of course its hardly all art, but you can make the argument that its valid for forms of entertainment like this.
8 to 10 years of unreleasing a film or tv series for example, could waive their copyright ownership as they quite clearly don't give a crap out getting any revenue from it and don't give a crap about movie fans. It doesn't have to be mass prints, they could easily sell DVD isos, burnt, downloaded or even full retail pressed dvds.
Something to talk to your culture minister and/or mp about