October surprise?

As Obama takes a lead in the polls, what type of October surprise might affect that or cancel the elections altogether?

• “Terror threat in UK approaching critical”
• U.S. Army Troops to Serve as U.S. Policemen?
• Next: The Mother of all Bank Runs?
• Bank Limits Fund Access by Colleges, Inciting Fears
• Russian Nuclear Bomber Flies Undetected to Within 20 Miles of Hull (on the British coast)