Hillary Clinton has slid to 70% likely to win the Democratic nomination for president in 2016. This is much lower than her peak of 85% in late June and early July. But, it is still incredibly high for a non-incumbent just after Labor Day.
Sources: Betfair, Hypermind, PredictIt, http://twopointoh.predictwise.com/politics/2016DemNomination
Most of her lost probability is going to Joe Biden, not Bernie Sanders. Sanders has increased his probably of victory slightly from high 7-8% to 11-12%, but he is still really unlikely win to the nomination. Biden, who is not even announced, has moved from 1% to 11-12% on the strength of him maybe announcing to run.
Should Biden run, he will likely jump another 10 percentage points, depending on the prior of him running. PredictIt currently has him at 50% to run. If he runs, it should be because he thinks it would be a possible to win, conditions are favorable.