I agree with the people that say "he wont", if you mean peace as in were everyone is happy and where pig fly the reason being is because kishi probably would want to end it with some sort of message and to simple say naruto created peace etc would in fact be lame, therefore i believe he most likly leave it with something like this "all should strive for peace, never give up" sort of thing. Believe it or not peace would actually mean no more ninja when you think about it because there would be no more violence therefore no need to wield shuriken or learn ninjutsu.