Just been watching NASA TV, streamed over the internet.
The main point is that NASA have been analysing the layered rock near Opportunity. They say that the evidence is pointing towards that these rocks were once saturated in liquid water. They've pointed to the 'blueberry'-like things as concretions formed by salt crystallisation inside rocks, and very high sulphate content of the rocks (up to 40% magnesium sulphate), as showing this. But they are still careful about saying whether the rocks were actually laid down by water.
So life may have once been possible on Mars.
Note that they did not find liquid water or any signs of life at this time.
