Michael, if you want to teach and be able to find tenure positions, my thoughts are to pursue the PhD. I have never had any faculty with a DSW. A good way though for you to get a real sense of what degrees faculty typicaly hold is to do a search of Schools of Social Work....CSWE has a directory of accredited programs www.cswe.org. Check out the CV's of the faculty. My thoughts are that you will find overwhelmingly the faculty will have PhD's. I am sure you will run across some faculty with DSW's, but I think you will find the majority will have PhD's.
There are some programs, for example, where faculty are expected to write grants and do research as well as teach classes. It all depends on the School of Social Work. During grad school I had some practice courses that were taught by adjunct MSW's....the one I can remember was a therapist in the field and she taught about the different therapies. My PhD faculty taught research courses, theory courses, and policy courses.