During my career as a game coder I have worked in large teams, small teams and also as a sole developer on indie titles.
Keeping Momentum
For small teams (1-2 developers), or while working on a one man project I find myself losing momentum after a while. Typically when there is no concrete timeline, once the code is halfway through there are distractions: getting the art, modifying design etc. these take me out of focus up to a point that the progress grinds to a halt, and the focus is lost.
This is the point when I start wishing I had a producer.
Even in small teams this is valuable. This can be a dedicated person, or one of the developers putting on a producer’s hat. The role calls for a responsible, well organized individual that would be in charge of keeping tabs on progress and creating, as well as maintaining, a momentum.
Getting Things Done
For indie projects where the developers are the stake holders, the most valuable resource is time. Using that time efficiently becomes a priority.
Getting things done is the main concern of a good producer, even if there is no official timeline. Also setting up internal milestones, coordinating between artists, deginers and coders and worry about the big picture.
Oh, I am definitely going to want one on my next project.