I have received the following information from one of Professor Hare’s former students:

Peter Hare died in the early morning hours on January 3, 2008. At the time of his death he was SUNY Distinguished Professor Emeritus of Philosophy at SUNY at Buffalo, where he had taught from 1962 to 2001. Peter was a long-time Editor of the Transactions of the Charles S. Peirce Society. He also served as  President of several philosophical organizations, including the Society for the Advancement of American Philosophy, which gave him its highest honor, the Herbert W. Schneider Award. A memorial session devoted to Peter’s contributions to the study of American philosophy will be held at the March SAAP meeting at Michigan State University. 

There is a "bit outdated" CV here.

UPDATE:  A personal remembrace from Professor Hare’s colleague Randall Dipert.