His Holiness is changing the conversation.
For decades the progressivists have been able to shift the Church around slowly but surely more in line with their preferences because, first and foremost, they were able to set aside their minor differences and act more as a block. Of course this is a simplification, but I think it is what happened. On the other side, those with more traditional leanings tend to like to fight with each other over nuances, albeit important nuances. The gross effect, however, is that these groups and individuals wind up fighting over their own trench and therefore cannot gain any real ground.
Another way the progressivists have been able to get their own agendas through was the use of patience. They use a sort of creeping incrementalism. Use the "boiling the frog" analogy, if you like. All they tried to do, craftily, was shift the paradigm we see things through a half degree at a time, every once in a while. Occasionally give it a little bump. After a few decades we wake up to find ourselves in a different Church.
The more traditional stamp of Catholic will often then demand that everything be brought back to the way it was, the way it ought to be, overnight. "Why doesn’t the Holy Father just fix this?", they lament. "Why doesn’t the bishop do something?", they repeat.
Changes made incrementally often need to be walked back incrementally.
Furthermore, the ironic twist of being in a position of power and influence means that you are often quite dependent, even more so, on others to implement your vision for change. The Pope is simply not capable of guiding the Church by fiat. To implement a plan, you must have enough people on your side who will carry out your wishes, that there is a reasonable chance for success. To launch a project, especially a large one, without the proper support from those who must actually do the work, could result in disaster, a real wound to your authority.
Pope John Paul II, over a period of almost three decades, slowly but surely, incrementally, shifted the fundamental alignment of the world’s episcopate. He didn’t attempt to work to quickly in his assignments so as to provoke reactions ever harsher than he received. He was patient in bearing even the promotions of men he probably knew were against his ideas. He bore it and kept working. Because of that patience, we have a very different body of bishops in, say, the United States. Along with the demographic shift, the biological solution, a new generation of bright young people for whom the dreamy "spirit of Vatican II" is a yawner, there is reason for great hope in the United States. And the rest of the world gets around to following.
Pope Benedict is now very wisely shifting the paradigms. He is building on the long, patient preparatory work of his esteemed predecessor. For example, he understood that there was at last enough support around the world and in the Curia in key places for him to promulgate Summorum Pontificum. In his years as a writer he provided a whole shelf of writings which explain his views. He is now shifting the paradigm in another direction. And even though it is an incremental shifting, his bumps are actually fairly dramatic.
He is changing ongoing conversations and introducing new themes for discussion, looking especially to the good will and energy of a younger generation.