Jeffrey Goldberg recently talked to terrorism expert Steve Coll about an al-Qaeda October Surprise. Coll's thoughts:
al-Qaeda leaders, maybe because they spend a lot of time trapped and bored in safehouses, seem to be obsessed with calendars. They like anniversaries and they pay attention to elections abroad. So I'm sure they have the American election in mind. My last well-sourced conversation is a few weeks dated, but last I checked the US intel system was very quiet in terms of "chatter" or other indicators of any attack in the U.S. What seems more likely are more attacks against US-affiliated targets in the Pak-Afghan region, coupled with media tape releases, similar to Osama's election-eve video of 2004. They like to be heard at big moments in American politics, and this campaign is certainly such a moment.