Have you read Caritas in Veritate
? He didn't call for some New World Order. He said that the world is growing closer and closer and now more than ever we are interdependent of each other (look at the world's economy), no matter where we live. We have a framework of international organisations and unions, but they are greatly in need of reform (he pointed out the UN for one), since amongst their priorities should chiefly be justice, human rights, charity, compassion, and Christian ethics. Also, he mentioned that certain superpowers (*cough* *cough*) still maintain the ability to circumvent International Law and could in turn violate the most basic of human rights with limited repercussions. Think of it more like a Synod of Nations (UN-ish, an authority), rather than a World Government.
Anyways, I don't want to drag this into politics more than I have already.
About prophecies about the Papacy, I have not heard of any, but I tend to put zero faith in them anyways. Otherwise Peter II is around the corner.