NBC News has a Senate source telling them David Petraeus will be appearing at the Senate Intelligence Committee on Thursday, where a closed hearing on the terror attack in Benghazi is on the schedule. CNBC's Ryan Ruggiero's tweeted that scoop comes from a "veteran senator":

Fox News has confirmed that scoop with a report of their own. And according to the Senate Intelligence Committee's release from October 25, tomorrow's hearing is a closed hearing on the 9/11 Benghazi murders: 

The committee will hold a closed oversight hearing on Thursday, November 15, with additional hearings to follow.

There were conspiracy theories (primarily from conservatives) that Petreaus's resignation was part of an elaborate Benghazi cover up, and that he might not have to testify. "Was Petraeus forced out to silence his account of Benghazi killings?" was the headline The Telegraph's Con Coughlin ran with—which sums up the (dead) theory in a nutshell.