There is another nice listing located here at the DemConWatch: Presidential Newspaper Endorsement List
They give you some historical context by noting with a (R) for Bush or (D) for Kerry who the newspaper endorsed in the 2004 Presidential election.
Currently on the list are 41 newspapers that endorsed George W. Bush in 2004 that now are endorsing Obama and 4 newspapers that endorsed John Kerry and are now endorsing John McCain.