coming back to the light doesnt neccesarily have to mean that everyone will forgive whatever he did.....but he will come back because thatz what naruto promised that it is a essential part to narutos plot (remember some where along he states that if he cannot save one friend what good would do to him to become hokage)....what most likely may happen is that sasuke may die at the end and at his last moments he may finally realise his mistakes....or realising his mistakes he may leave for the unknown forever........cuz u also have to kep in mind he is the last of the uchihas..if he dies the clan dies with him.....another thing to remember is that....in all of the fights between the descendants of the two son..the elder brother's descendant always loose continueing the hatred(elder brother, madara etc.. the las t fight naruto vs sasuke some thing different has to happen not that naruto will loose but something that must end the cycle of hatred...)
