In 2006 Italy had world class player in every position, maybe except for LB and ST.
Buffon, Nesta, Cannavaro, Zambrotta, Pirlo, Gattuso, Camoranesi, Totti and Del Piero and they had the likes og Grosso, Toni, Materazzi, Perrotta and De Rossi, who are also a fine players.
Now Italy, has only two players who can call themselves world class, Buffon and Chiellini. While the others are either washed up legends, or simply average players. Marchisio, De Rossi and Rossi are one of the few who aren't average.
You can class Cassani, Maggio and Balzaretti as good players based on their form with their clubs, but who knows if they can hack it at the top stages.