It is no doubt that the bin Laden tape was a message. A fool could surmise that. Bin Laden also mentioned the FL school where Bush was on 9/11. Think Beslan? Maybe... go guess.
They knew that a fresh threat-of-attack favors a Bush win on Tuesday. This was NOT just a PR opportunity.
The message was an encrypted command.
God help us if so. Many schools are used for polling also.