I guess they felt that they needed to get him now so as to get back into the title race, or just to make sure that they keep the fourth and final CL spot.
It all depends on the price as far as I'm concerned because paying alot of money for a player who's the wrong side of 30 wouldn't be Moggi's most intelligent move yet.
I don't like the deal one bit. Stam would be a good purchase, but only for the right price, and Stankovic, I don't like his attitude. Juve can do better than Stam and Stan.