More details of The Biggest Loser 2012 have been released online. According to an article by TV Central:
"The seventh season of Network Ten’s hit reality series ‘The Biggest Loser Australia’ has started production. The 2012 series, currently filming in Sydney, will revert back to its original singles format where contestants aim to lose weight throughout the series to be the ultimate winner, make a healthier life choice and take home the large prize money.
The Australian adaption of the US reality show premiered in 2006. It is hosted by former Olympic swimmer Hayley Lewis and trainers Michelle Bridges, Shannan Ponton, Steve Willis (The Commando) and Tiffiny Hall.
The new season of ‘The Biggest Loser Australia’ begins early 2012 on Ten."
As we know from Tiffiny, she will return for the new series. Furthermore, filming is expected to take place over 7 months.