Basecamp (Score 3, Informative)

It sounds like what you're really looking for is a project management solution. Assigning tasks (such as 'write a story about x', 'cover the situation in y for the next 2 weeks'), settings deadlines, and co-ordinating groups or individuals - this all has very little to do with 'content management' as most people think about it.

Drupal has you covered with organising your content (taxonomy), tracking history and versioning, and establishing an editorial workflow (actions and workflow). But it doesn't have project management well covered (the 'project module' is too specific to software development), and there are no Drupal modules that I'm aware of, for integrating such management with actual content handling.

I think that Basecamp would do the job best for you. It has all these PM facilities, in a very intuitive and easy interface.