The site had previously revealed that a mysterious event was scheduled for the facility with the venue booked through mid-September. However, their sources have now confirmed that Apple is the one holding a "trade show" between September 4th - 10th.
Today a trusted source confirmed to us that yes, the activity at Bill Graham is indeed preparing for an Apple event. Our source, who wished to remain anonymous due to the extreme privacy surrounding the event, has shown us documentation from event logistics indicating that Apple is renting the building through September 12th. This timing is consistent with what we were told by a security guard on Monday.
Corroborating reports that the event itself will take place on September 9th, Grove Street in front of the auditorium is scheduled for closure from 6pm on Tuesday, September 8th to 11:59pm on Thursday September 10th. In addition, Fulton between Hyde and Larkin will be shut down on Wednesday September 9th between 4am and 11:49pm. That area is typically used as a staging area for equipment.
Apple should be sending out invitations to its press event within the next few days. Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.