Intelligence allows us to evolve very rapidly. By the next century, I imagine that direct genetic manipulation will be commonplace, and this will enable us to self-select genetic specific traits for specific social niches.
We will undoubtedly develop increasingly sophisticated technologies of communication, and increasingly sophisticated technologies of control. This will spur the arms race between our growing collective consciousness and small groups in power, which we already see in an early form today.
Examining our own bodies, we are made up of many different types of cells working in harmony to accomplish specialized tasks. Given our progress on genetic modification techniques, I think it is likely that we will develop a global human organism with many different collections of human-esque creatures. Some of these will be more self-aware than others; some will have control over specific aspects of the communications systems; some will have more ability to direct the large-scale activities of the organism; others will operate on a more local level.
Thinking about our potential evolution reminds me a lot of a game of Go. Lots of new territory is opening up right now. When I first started playing Go, I assumed that the player which first established an advantage would inevitably grow to subsume the entire board. However, that is not the case. Even when one player has gained a clear advantage, it is still possible for the other to create living niches.