I have been taught, but now do not believe, that it is correct to use 'shall' in the first person and 'will' in the second and third persons for the simple form of the future tense, and vice versa for the emphatic form. This is an ideal example of picky grammarian rules. I now endorse the Swedish usage, whereby 'shall' (skall) indicates an essentially inevitable event, 'will' (vill) indicates an intention, and neither is the standard means of expressing the future.

(BTW, the sense of the English will is better expressed in Swedish by 'borde' - 'vill' being used strictly to indicate intention or desire. Thanks to bigmouth_strikes for the advice.)