I think Napoli peaked... can't see them repeating this season's performance. They hit their ceilling, having good players who mesh perfectly together, not old but not young enough to attract interest from big teams which would basically force Napoli to sell them (Hamsik, Callejon, Mertens). I expect a decline next season, even if Giuntoli has done an amazing job with the resources he has.
I don't see a better season to beat Juve than this last one. If Marotta plays his card right, we could really extend this streak...
I don't see Roma pulling a Napoli performance next year, also. Inter could bother, since De Vriij and Lautaro are good additions. But I don't think they top Roma's performance of this season.