Video Production and ownership of rights

What rights do production house retain over the content they produce? Do they ever share ownership or have it outright? What are other ways video production houses could put the fruits of their labor to work? It seems that a lot of them don't own the rights to license footage they shoot but can only use them for promotional work on their sites. What rights would you like to retain if you were these companies and how much leverage do you have in negotiating the contracts for the rights? Can these houses sell or license any of their footage? Would they be interested in a service like the one that Cutcaster will provide to license their clips/footage to others in film making or advertising?

I've noticed that many of them produce commercials, documentaries, feature length films, TV episodes, corporate videos, stock footage etc. etc. What are the different ways these companies could sell their content to add extra revenue to the companies bottom line? Is it worth the hassle for the to upload their clips to stock sites? How can these companies work with a company like Cutcaster to carve a new marketplace out in the future?