Sorry @zopyx , I forgot to mention that Kaltura is probably no longer part of the equation.
I was hoping, by going back to Plone 4, to follow up on what was suggested by @hvelarde.
The folks for this project evaluated the CE version of Kaltura, it is incredibly buggy, and is lacking too many of the functions needed. The other features are only available in the commercial hosting, which would cost many tens of thousands USD per month/year, based on the quotes. Kaltura is much more affordable than the several other competing video products, but causes more problematic vendor lock-in concerns, and would greatly reduce their budget to be able to make new content, just covering the Kaltura expenses.
They are working on a front-end, and possible peer-to-peer options to greatly reduce bandwidth expenses, but still need a central user community driven content platform, Plone ( ? )
So, Kaltura is unlikely to be any longer in the picture. It is possible a Plone setup may be the video repository down the road maybe . They were looking at Plumi, but he said it had far to few features for content providers. I whipped up a Plumi instance this weekend for them to try out with more flexibility than the previous online demo they tried, to give them a second chance to be sure.
But meanwhile, if I can just whip something up, grabbing from youtube, vimeo, and other sources, arranged in various ways within Plone (like the original screenshot in this post), such a collection.
Then it may be possible to encourage the extra time and effort needed for such integration.