I actually have wondered about this myself. In terms of human evolution, we are not really under selection at all. There may be selective forces that can shift some allele frequencies one way or another locally but the sort of radical shifts in the gene pool needed for speciation are not in sight. I remember a lecture by Richard Lewontin where he said that a catastrophe killing all humans on the planet except for the Kung would still leave about 85% of all human genetic variablility represented. It is hard to imagine much evolution occurring in such an environment when most selective pressures are relatively weak. Even disease causing agents such as HIV are poor selective pressures since they allow people to breed before killing them. It does not take much migration to cause a lot of admixture. If you couple that with a big decrease in isolation by distance, the human species is becoming one gigantic admixed population. Whether this remains so is not predictable as huge shifts in the climate or some other catastrophe can change things radically..even for successful species or groups...look at what happened to the dinosaurs..or trilobites.
I can just see the grant application, Testing of the neutral theory in human populations. Expected duration of experiments...10,000-100,000 years . PI..not born yet.