Team rotation, what an interesting term. But I really think it is based on 2 factors, the players to rotate and the occasion
Let's talk about the players
For a successful team, it takes the players and the coach to get well together. And the coach must know which players to choose from, not juz anyohow pick a player and dump him in that position. A coach must determine the starting 11 who will bring the best results out of his team. In our team, we have every compartment which is complete, except for the RB position. Zebina's lack of concentration is costly, rotating him between Balzaretti + Blasi + Pessotto is a good strategy, however when playing against a strong opponent, it is important to determine the best player among the lot. For our attackers, we have Zlatan, Trez, Mutu, DP and Zala. And Capello has made up his mind as to which players will be playing. With Capello's preference to tall strikers, Zlatan + Trez will get the nod, but if I were the coach, I would rotate Z, Trez and DP, with Mutu behind the 2 instead of Nedved. I would determine which striker performs better, and take the other player off, something like that 1st few games last season.
Occasion
Speaking of the starting 11, it's impossible to play all of them throughout the season becos we will probably lose due to exhaustion, especially our hectic CL + Serie A schedule. We would be pitting against strong teams for matches to come. So I would say, the best 11 has to start against the strong teams and grabbing a win is important. I wouldn't mind giving our 2nd team players a try against weaker teams, but I wouldn't change the entire squad. Like instead of putting Trez - Zlatan, I would opt for Mutu-DP-Zala trident. For LB we can play Chiellini instead of Zambro all the time, for RM we can let Olivera play once in a while in place of Camoranesi. for CM, Blasi/Gianni can take Emerson/Vieira's place since the latter 2 would be suspended someday. Nedved to take Mutu's place, and place Nedved as a LM. I would use squad rotation only somwehre in the middle of the Serie A campaign + Coppa Italia. I don't like the idea of using team rotation early in the season, as our starting 11 needs to get games for their experience.
Oh yea, don't rotate the team as much as Inter, otherwise we would experience something like the Palermo 3 - 2 win against them becos Mancini rotated the team at such a period.