WordPress isn’t well-equipped for content collaboration. In fact, thanks to its fancy post locking feature, WordPress is streamlined to enable the opposite of a collaborative editorial workflow. It’s designed for one user to work on a post while locking all other users out.

Isn't that something? Automattic has a nifty plugin in its arsenal called Edit Flow and they have the resources to provide a similar feature set that this plugin offered. Unfortunately, Edit Flow development seems to be at a stand still.