I foresee the day that the ALP as we currently know it will split and the left faction will have a genuine coalition with the Greens and the right will stand alone and try and be that middle ground. Much of the "problems" with Labor has been this dichotomous position they have federally when the leader traditionally comes from the right and the deputy from the left. The left are the most vocal internally and the right most vocal externally (ie to the media with leaks etc).
Of course Gillard's takeover changed things - she was from the Victorian left, but her leadership within the party made her the inly viable choice for the overnight "knifing" - but she knows that to remain where she is she has had to pull to the right.
Of course in politics timing is everything, so it would probably take some significant event/saga to see such a split.