You are right, the conclusions might seem obvious, but nevertheless it is a great step forward that finally somebody in IT has taken the effort to make a statement about developer productivity that is based on empirical data.

Too many discussions on this subject are just based on intuitions and gut feelings, really amazing if you consider how much of an exact science IT is otherwise. I hope there will be more of this kind of fact based research in the future. I can think of a few more subjects, e.g. productivity gains by switching from an imperative to a functional language.