Well, Spain won EU champs while Barcelona won the CL aswell. So most their players had a very long season.
Also Iniesta and Torres, assuming they are fit enough to play, will be in better condition and more fresh as they missed out the last months due to injuries.
Eventhough I agree Torres is a key player for Spain, I do believe Villa is more important. The great advantage of Spain is that not only their strikers score alot of goals, but also their midfielders do, which is a great asset.
I don't know about Italy, tbh I don't know their squad very well. Most of their players come from Juventus, who played a very poor season this year. Alot of key players have left (Nesta, Totti) and others are over their top (Cannavaro, Grosso, Zambrotta, Toni). Their strikers aren't known to be amongst the best (eventhough Di natale and Iaquinta are good strikers).
I don't know, I think they will miss the experience of alot of players that quit or didn't play a great season. I don't think they'll reach the semi's and tbh I surely hope they don't