They are only stakeholders through imposition of laws such as those proposed.
A more likely future is that most content will be new and not controlled by MPAA or RIAA. These legacy content holders will fade from relevance as their content is duplicated beyond their control and, even more importantly, rarely ever accessed.
I like your optimism, bully for you, and that's a great idea. But I fear that the ISP/"rightsholder" conglomerates, like Comcast/NBC, will only let very select, RIAA and MPAA owned content through.
They already give priority in their cable packages, and they already own Hulu.
Content delivery is controlled by content creating big media IP holders. Obviously they will try to keep competition down, especially new media that understands how the Internet makes information free.
I think it will primarily be determined by who can support (fund) the artists who are making the content people want to watch.
Of course, easy, essentially-free, world-wide distribution will make it harder for RIAA and MPAA to maintain control over the flow of mainstream art.
Viewer-funded (or even mini-investor funded) models could be viable. I'd imagine they could even compete favorably with large production studios if the right structure was found.
A more likely future is that most content will be new and not controlled by MPAA or RIAA. These legacy content holders will fade from relevance as their content is duplicated beyond their control and, even more importantly, rarely ever accessed.