From a previous thread, I believe that was supposed to be 14 days. Plans can change, of course.
I actually have a perfect itinerary for 143 days, oh well...
Seriously, I think you can easily spend 2 weeks just in QLD. You can go up to Far North Queensland (FNQ) for the Great Barrier Reef. You can spend a day or 2 at the theme parks between Brisbane and the Gold Coast, and of course, head to the Gold Coast or maybe the Sunshine Coast...