People need to stop obsessing about exact formations.
As Ferrara has shown with the 4-2-3-1 and, to a lesser extent, the 4-3-1-2, he is willing to give players some freedom within their role.
This means you could have some sort of in between sort of formation with players not really occupying orthodox positions.
For example:
Buffon
Caceres-Cannavaro-Chiellini-Grosso
Sissoko----Melo
Camoranesi-----Diego--------------
--------------Trezeguet-------Del Piero
Something in between a 4-2-3-1 and a 4-3-1-2.
I'm not saying this would necessarily work, all I'm saying is that people should not just be thinking in terms of standard formations all the time, as we have some very intelligent players who can adjust and play slightly different roles to make a system work.