Strong, controlled performance from Juve.
Was never going to be an open, exciting game - unless one (or both) of the teams or coaches got things badly wrong.
Milan had no interest in doing anything but waiting for counter-attacking chances; Juve weren't going to take risks to force things.
The key thing for Juve was to stay patient and not fall into the trap of committing too many men forward or playing risky sideways passes that could have left them vulnerable with several men wrong side of the ball.
Juve got the balance right and there was enough quality in the final third - mostly through Llorente and Pereyra in the first half and Pogba in the second half - that Juve were going to create enough half-chances that you would expect them to take one of them and win the game. As it happened, Pogba did something brilliant and created a clear chance so Juve didn't have to rely on taking a difficult chance.
In being cautious in the first half, Juve came pretty close to playing an orthodox back four. Asamoah wasn't pushing high up and that allowed the three centre-halves to shuffle a little across to the right and leave Lichtsteiner with virtually no defensive responsibilities. I liked the move because it reduced the risk of getting caught three versus three, as can happen with 4-3-3 against 3-5-2. With Lichtsteiner playing as a winger, Pereyra was then free to play very centrally and it was him bursting through the middle of the pitch that produced Juve's best chances in the first half.
In the second half Juve - having established that they were pushing Milan so far back that they couldn't threaten on the break - returned to playing in a more orthodox 3-5-2 (or 3-5-1-1, given the role Tevez now seems to be playing) shape and continued to boss the game and look capable of scoring without taking any risks.
Thought it was interesting that, in contrast to Juve's last couple of games, Juve barely attempted a cross from open play in the entire game. It could be because Allegri thinks Milan aren't vulnerable to that, but I'd be susrprised if that is the case given that everyone is vulnerable to conceding from crosses when playing against Llorente. More likely that it was an anti- counter-attack measure (like Conte with his short corners) as you do tend to need to commit a few players to the box to be likely to score from a cross (especially if you don't have great crossers.
Instead Llorente was very much the focal point of Juve's attack for most of the game. The whole plan was playing pretty much through the middle, with Llorente occupying Milan defenders and laying balls off for the likes of Tevez and Pereyra moving forward from deeper positions. It's quite a safe way of attacking because you can be very dangerous with only two or three players risking being caught ahead of the ball should things go wrong.
Anyway, good team performance with good game-specific plans from Allegri.