My predictions for next season are:
1. Napoli
2. Inter Milan
3. Juventus
4. AC Milan
5. Atalanta
I didn't include Roma in my list because I feel Roma hasn't convinced me enough with their sometimes inconsistent performances. However, I have no doubt that Roma can secure a Europa League spot, as this club always strives to maintain their Europa League position if they fail to qualify for the Champions League.
However, predictions can sometimes change, and we don't know whether Napoli can defend their title because the Italian League is very competitive and has a different champion every season.
I'm confident Napoli can defend their title. Their performance was quite good last season, and that could be a benchmark, especially with the lack of changes to their squad, which could allow them to continue as they did last season.
As for Inter Milan, I have serious doubts. They don't seem to have made any significant changes. The recent change in manager has raised many doubts, as their new coach, Chivu, lacks experience.
However, for Roma, I predict a turnaround, as you mentioned. They are building a stronger team, and at the end of last season, we saw positive changes, which could continue. So, I predict Roma can compete fiercely at the top of the table for the Scudetto next season.
Do you know when Napoli was able to defend their title last time? I don't know if they ever did.

Except for Juventus Turin there has been no team in many many years that was able to defend the title in two consecutive years. To claim that you are confident Napoli will defend their title is not comprehensible to me in Serie A. It's a volatile league with changing Scudetto winners from year to year.
When Manchester City was on top of everything, it was ok to say that one is confident Manchester City will defend their title. Or that Barcelona will defend their title in La Liga. Or that Bayern Munich will defend their title in the Bundesliga.
But Napoli will confidently defend their title in Serie A? Against Inter Milan and all the other equally top teams? Predicting that in Serie A is like lottery. Inter Milan will be a top notch team next season, there is no doubt about that. Juventus Turin could turn some of their draws from last season into wins this season and be part of the competition for the title. AC Milan has surprisingly won it not too long ago. I think three years ago it was.
Serie A is difficult to predict.