I think for a lot of us, he popped our cherry (Scudetto) and for that reason, even if he's a whiny bitch in the later years of the relationship, he's still memorable.I can’t believe he will get Nazionale and I cannot believe he’s in Grande Inter. What a lucky man.
Mancini will do jackshit with Italy. He has no tactics to start with. Worst Inter manager in the last 10 years.
I think he'll do a superb job picking the best squad available and then picking a formation that will actually allow said players to flourish (i.e. letting Insigne play as a winger). Tactically he won't have a clue, as per usual, but that's okay. You don't need tactical superiority to beat SWEDEN, you just need to not shoot yourself in the foot.
As for Nazionale, he might be a good fit because he has no ability to ask for transfers but he will simply pick those he wants.
Compared to some recent choices FIGC has made, Mancini is a big improvement on the likes of Ventura, Di Biagio and Donadoni. The bias against Mancini on this forum is a bit silly, but FIF always likes to scapegoat the coach (unless you win the treble).
That said, Mancini may not suit the rebuilding process specially because Italy lacks the kind of players he usually needs - the kind of players who can physically dominate the midfield for example. Someone like Sarri may have been the best fit for an Azzurri revolution.
Tactically, I can see Mancini playing a 4-3-3 with attacking wingers. But in the midfield is where his biggest problem lies as the likes of Verratti, Cristante or Pellegrini may not suit his style, we will probably see more players like Jorginho, Parolo, Barella or even Gagliardini.