Despite the fact that its late revelation embarrasses the FBI - who failed to tell anyone, including the 9/11 Commission, about it - the latest story of Atta's Florida friends (reminiscent of Hopsicker's reporting) was presumably released to remind Americans of the Saudi connections to the September 11 attack, a big part of the official mythology required to divert attention from the real perps.  Short summary:  Atta hangs out at home of people, related to a prominent Saudi family, who suddenly disappear before September 11.  Of course, if you think about the details, the story falls apart (which is presumably why the FBI didn't use it until a big Saudi reminder was needed for the tenth anniversary).  The problem details:

1. The family disappeared two weeks before September 11.
2. They left so hurriedly they didn't have time to pack anything.

These facts don't hang together with being part of a conspiracy with Atta. If they knew what was going on, why leave in a mad rush, but two weeks early? It doesn't make sense.  It appears that something terrified them into leaving immediately, but that something didn't have any direct connection to September 11.  It is likely they were set up, introduced to Atta and then warned that their lives were in danger if they didn't immediately disappear.  In other words, they were meant to be part of the mythological connection of the attack to the Saudis.

It is common to see these strands built up connecting various groups as scapegoats to be used after the event.  For example, the JFK assassination is full of such strands, various frames of guilt to be used as and when necessary by the real conspirators.  This one is an obviously faulty story, so it wasn't used until they needed a last-minute anniversary distraction. xymphora