According to the Linux.Conf.Au 2006 organisers, there has been a massive number of submissions for LCA, so they have had to delay speaker notifications and attendee registrations.
The new dates are as follows:
September 28: Speaker Notifications Start
October 3: Speakers Announced
October 6: Program Announced
October 7: Early Bird (cheaper) Registrations Open
November 18: Early Bird Registrations Close (Prices Rise)
Naturally, registrations will close when places run out.