The sept 3 court appearance is a committal mention, a procedural matter to make sure all parties are moving towards doing what they need to do like the prosecution handing over the evidence they have already been ordered to to by 20 August.
There will likely be more of these mentions and at some point a date for the actual committal hearing will be set for a magistrate to determine if there is sufficient evidence on which a jury could convict to send the defendant to trial in the District Court or Supreme Court. Some more info about the committal process is in this link
http://www.justice.qld.gov.au/justi...-in-court/magistrates-court/committal-hearing
I think most people charged with murder get committed to stand trial as the police would usually have "sufficient evidence" either at the time of arrest or by the date of the committal. Obviously though the magistrate has to also be convinced that there is "sufficient evidence" The standard of proof is much lower than what is necessary to convict in a trial by a jury. For our American friends it is our equivalent of the US grand jury process, though quite a bit different.
If committed to trial by the magistrate, in this case due to the severity of the charge, namely murder, the accused person would ultimately be tried in the Supreme Court of Queensland.
GBC's committal hearing is not going to happen before next year. The forensic accounting investigation I think from memory was likely to take until November. As for a trial, hopefully there will be a new judge appointed soon to ease the current backload of trials. So maybe another year after the committal hearing for a trial. It is hard to know but it will be a long time.