Just a quick point on the "oil slick/fuel" that has apparently been spotted - it should be easy to determine (certainly by taking a sample and analysing, and possibly just by looking) whether the fuel oil seen in the water is kerosene (and thus possibly from the aircraft) or comes from some other source (eg. a ship dumping tank residues).
There's a huge difference between jet A1 and oily ballast, and IMHO it wouldn't be difficult for someone who knew what they were doing to tell the two apart.
First, jet fuel is very close to diesel in its physical and chemical properties. So it might need sophisticated analysis to make sure it is indeed jet fuel. If that is even possible after several days of exposure to open water and evaporation of the lighter parts of it I don't know.
Second, even if it was jet fuel, it is no positive proof, that is is from AF447. It could be a tank ship carrying jet fuel or cleaning its tanks...
Positive proof would be only unique debris.
-Aircraft parts of an A330
-unique Cargo consistent with the manifest.
-Human remains
after DNA or other identification
The oceans are full of trash.