Have "design thinking" and "social innovation" become permanently intertwined? You'd have to think so based on Tim Brown's book and the prevailing discourse at any major design/innovation conference (SXSW, PICNIC, GEL, GAIN, LIFT). There seems to be a firm belief that you can't establish any cred as a designer these days if you haven't applied design thinking to a major social issue of some sort (health, energy, education...). Similarly, it would seem that social innovation (or social entrepreneurship) is hopeless without a designer at your side.
I strongly believe that interaction design is central to solving the major issues facing our society today (this is probably no surprise coming from an Interaction Designer). Large scale challenges like the environment and healthcare can only be addressed if we can positively influence personal behavior on a large scale in a sustainable way. Our work on Project Masiluleke, for example, is focused on motivating young men in South Africa to test earlier for HIV, before they are symptomatic. According to a recent article in the NYTimes a new mathematical model developed by the WHO suggests that the AIDS virus could be virtually eliminated if people tested earlier (before they have symptoms) and are immediately put on ARV's: "Whether this could work in practice is problematic. It is not clear how one could persuade people who are not feeling sick to get tested every year."
Behavior change is at the core of good interaction design, particularly when you design for social impact (this has also been referred to as 'Decision Architecture'). If I was starting an Interaction Design program (like Liz Danzico at SVA) or taking one over (like David Malouf at SCAD) the one academic subject I would be sure to cover is Behavioral Economics.