A PhD based on tutor-web research: Dr Anna Helga Jonsdottir defended her PhD thesis on April 17, 2015. The thesis title is "Development and testing of an open learning environment to enhance statistics and mathematics education". The work underlying the thesis was largely based on development and experiments using the tutor-web. A copy of the PhD thesis is available at http://bit.ly/PhD-AHJ and the thesis also provides the single most comprehensive description of the tutor-web.
Great news. I stumbled across this coin on twitter today. Looks like a worthy cause. I will pick some up tomorrow.