I stumbled on a cool new feature at the American Historical Association's Web site: a database  of all dissertations currently in progress by graduate students in history. The 4,363 dissertations are searchable by institution or key word.
The key word search is a nice way to find out what's coming up in the field. For those who fear that topics like foreign policy and war are getting too little attention, relax - many young scholars focused on these areas.
But as with any key word search, you need to be careful: "War" yields dissertations with topics such as "What They Fight For: The Men and Women of Civil War Re-Enactment" along with more traditional military history.