The world champions have six players in their squad who featured for a faltering Juve last term and Iaquinta wants to forget their dismal seventh place finish in Serie A and create a new way of thinking for South Africa.
"We've got to change our attitude because the approach we've had this year has definitely been wrong. We've got to take responsibility," Iaquinta told Reuters.
"We have to practically change our entire mindset."
Gianluigi Buffon, Fabio Cannavaro, Giorgio Chiellini, Mauro Camoranesi and Claudio Marchisio are the other Juventus players in the squad and all could start during the June 11-July 11 tournament alongside Iaquinta.
Italy coach Marcello Lippi has been criticised in the media for relying too heavily on his former club's ranks, although he did jettison Juve duo Fabio Grosso and Antonio Candreva from his provisional squad.
Juve lacked cohesion and confidence all season but soft-spoken Iaquinta, a favoured workhorse of Lippi, believes Italy's 2006 triumph can still be repeated.
"We know we can have another great World Cup, we have all the assets to do it and I can't wait," said the 30-year-old, who could be used on the right in a 4-2-3-1 formation in their Group F opener against Paraguay in Cape Town on June 14.
"That's up to the boss but he knows I will play with anyone and wherever he wants."
He struggled when starting in the unfamiliar right wing role in the 2-1 friendly defeat by Mexico last week and came on as a late substitute in Saturday's 1-1 draw in Switzerland.
Iaquinta, a squad member in 2006, holds the ball up superbly and has improved his eye for goal in recent seasons with the sort of trademark finishing which former Azzurri Filippo Inzaghi was famed for.
Iaquinta's biggest problem has been his fitness and he missed the majority of last season with a knee injury, although now he could be fresher than other World Cup strikers coming to the end of a long, tiring campaign.
"Now I'm fine physically. I had five months of injury and it wasn't easy to recover but now I'm definitely better," concluded Iaquinta, complete with a new spiky haircut.
Italy arrive in South Africa on Wednesday.
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