An asymmetric 4-3-2-1 makes sense to me if we intend to have Pirlo as a starter and Sanchez reasonably center (supposedly his best area).
-edit. A good transfer window/formation, for me...
---------------------------Buffon
---------------------------Storari
Lichsteiner-------Bonucci----Chiellini----------Ziegler
Sorensen/RB----Barzagli----Sorensen/CB----De Ceglie
-------------Melo----------Pirlo----------Inler
-------------Marchisio---*Aquilani----*Pazienza
----------Krasic--------------Sanchez
----------Quagliarella-------Del Piero
----------------------------Matri
----------------------------Toni
Sorensen stays as aux. RB if no one else is brought in. If not, 3rd or 4th CB.
Aquilani stays only if he can be brought in cheaply.
Pazienza arrives if no other free/cheap signing is available, or no youth prospect is deemed worthy.
If Pepe isn't (and he shouldn't be) bought, we only have Krasic as a true winger. 4-4-2 isn't necessary, therefore, and wouldn't work anyway with the personnel we have and are targeting.