This sounds like a refreshing change. Leadership has been a major talking point in the program recently, and not just from fans, but players as well. The way I look at it, leadership skills exist in certain individuals, and some leaders are better than others. If I'm going into battle, I'm looking for those select one or two guys that I will follow every single week. While the rotating captains doesn't change who is and isn't a leader, I think it's a more definitive statement when one guy or two guys get that captain badge and are looked at in this role every single week. I associate it with the military. Although I've never been, I wouldn't want to follow one Captain into battle one week, but be told Joe Schmo has been made honorary Captain the next week and has all the same priveleges. It doesn't make sense, at least not to me.
As for the blackshirts, I think they should be given at the beginning. They're for the starters, plain and simple. They're not an achievement to be earned during the season. While the blackshirt reputation stands for excellence, you're not required to be excellent to have one - you're just required to be a starter. When you postpone handing them out, you put them on a bigger pedestal. And, as we've seen the last couple of years, you hand these shirts out and things go massively wrong the next week. Hand them out at the beginning of the season and you avoid putting them on such a big pedestal.