Imo this is what is going to happen. Labor will continue to slump in the polls, there will be minor front bench reshuffles and a few new faces to try and keep some faith in the NSW government. Then about 6-8 months pre-election Rees will receive a leadership challenge from a 'young, up and coming' leader who will promise to improve state education, spend big on public transport, health and all that jazz. Sure this means more debt, but the average New South Wale-ian will love it and eat it up. This new leader (possibly female, which would add more momentum) will then pit them self as the crusader in shining armor who will revolustionize politics and rid NSW of corruption forever.
Liberals will try to run a smear campaign saying, you've seen it all before, but this new, charismatic leader will take everyone by surprise and turn around the polls. Liberals will trip over themselves thinking 'How the Fu- did this happen', leading to a Labor 5% win at the election.
/rinse and repeat four years later after it all fails again. Humans are stoopid.