Conte is one of the most important people in Juve's history. He was fundamental to take the club out of its worst moment in more than 100 years of history, started by Calciopoli.
The way he left was horrible, not the decision itself. This makes him less admired for Juve fans, since he fucked the club on that, but it doesn't take away the huge part he had to rescue the club to immediately being back to Juve status again - dominating Italy.
Good luck to him. But I don't really expect a renovation. He probably intends to stay only till Euro, having a 2 year contract. He can and probably still will go with Buffon, Barzagli, Bonucci, Pirlo, etc. He is a very conservative coach and doesn't trust youth. I don't see big changes at the NT, neither a more than a small chance of winning the Euro solely based on Italy's tradition.
His version of the 3-5-2 will be better than Prandelli's version, because Conte understands the best way to implement it. Pretty sure he will give more chances to younger players, and will make the players run their fucking bollocks off a lot more than we've seen recently. Italy since 2006 (besides a freak showing in Euro 2012) has been majorly disappointing, and as much as it annoys me that he left us at the beginning of pre season, this is easily the best appointment Italy could have made and the most exciting since Lippi taking over in 2004.