Well, I hope after 183 comments that it is clear to everyone that considering oneway=yes for pedestrian is most of the time wrong and that highway=* which are only allowed in one direction for pedestrians is a rare case.
Even if we find some situations where it might not be ambiguous, I have to ask if we want to make exceptions (plus probably exceptions from the exceptions) or if we want to make it clear and consider oneway=* only for vehicles (plus horses?).
Regarding editors, presets could include the information that oneway=* is not for pedestrians and offer another tag.
Regarding oneway:foot vs foot:forward/backward, I would prefer a clean cut and use the latter.