Aguero, Benzema, etc might be great talents and all, but we just don't need another youngster right now.
With Criscito, Nocerino, Palladino, hopefully Giovinco (I don't mention Molinaro who I don't consider talented enough and Chiellini, a confirmed player for me), wa already have enough youngsters. If we're able to transform three of them into Juventus regulars for the years to come it will be a succes, yet it takes time, energy and will cost us some points in the future.
What we need is one confirmed player in the midfield to take over from Nedved, and one confirmed CB, as it's clear we lack leadership in the back.