What were Macbeth's predictions in Macbeth?

The predictions that the Weird Sisters make for Macbeth are that he will become Thane of Cawdor and that he will become king of Scotland.  However, there is some debate about whether or not these should be counted as predictions.  The first, that he will be Thane of Cawdor, is actually not a prediction: Duncan has already named Macbeth the new Thane of Cawdor (at the end of Act 1, Scene 2); Macbeth just doesn't know it yet.  Therefore, they aren't predicting the future -- they are simply aware of this knowledge before Macbeth is.  As for their prediction that he will become king, it is unclear whether they actually know this to be true because they can see the future or whether they only tell Macbeth that the crown is in his future in order to see what he will do in order to attain it.  In other words, it is possible that they are only trying to manipulate him, to get him to corrupt himself, in order to become king (an interpretation that seems valid based on their sheer petty maliciousness and the joy they take in messing with people -- note their conversation in Act 1, Scene 3, where the First Witch seeks to punish a woman who would not share her chestnuts).