Cloning technology and genetics are on the edge of allowing us to bring back a previously extinct species. If such is demonstrable, we will have the tools to save species on disk until humanity's numbers start falling. I've left this until last because it is possibly the most explosive change of the lot and is the one that will aide and abet many of the above and change society into something that will be unrecognizable to Second Millenium minds. Precisely what those changes are is almost certainly beyond detailed prediction. The Second Millenium opened with some of the elements of the birth of the Nation State in place, and in many ways the millenium is the story of the growth of that entity and the battle between it and its competitors.
States are hierachical.
They work well in a reality that has relatively slow information flows, and in which the collection and particularly the collation and analysis of information is very costly. In such a world information moves vertically. It is analyzed on the way up and then distributed from the top downwards. But communications technologies have been eroding that ability to control and now as the internet goes into full flower over the next few decades, it is likely to undermine the very concept of the state and many of the concepts built around it. I cannot predict where this will lead.