Contingent on losing her appeal, Amanda Knox will be extradited to Italy to serve her sentence.

I've noticed that this kind of formulation of a prediction is defective for the purpose of calibration on things like predictionbook. If, instead the prediction was "Amanda Knox will be lose the appeals process AND Amanda Knox will be extradited", to complement your other question then the predictions continue to mean what predictionbook intends them to mean and if people answer both predictions then they have also provident the conditional prediction information.

Contingent on losing her appeal,

This is ambiguous, of course; technically, the "appeal" level is what just happened. The next stage is a second "appeal", at the Supreme Court. (Italian terminology actually uses two different words for the two stages, but they both translate as "appeal" in English.)

Amanda Knox will be found guilty by the Italian Supreme Court.

Again, to be technically correct, what would happen is that the finding of guilt by the appeals court (the thing that just happened) would be confirmed by the Supreme Court.

...because if you're talking about practicalities instead of legal formalisms, what actually happened was that Amanda Knox and Raffaele Sollecito were found guilty by the Italian Supreme Court last March.