Humans continue to evolve, but will remain one species for quite some time.
Genetic mutations happen all the time. Modern humans already almost a foot taller than 300 years ago. Europeans had developed resistance to plague by 1600, while Native Americans did not. But it did not make them into new species.
New species appears when mutations go so far that new species can't cross-breed with old species. For this to happen, "new species" needs to be isolated from an old one for many generations. And this is not possible in modern human society.
Evolution of the homosapien so far has been predicted as larger brains. They predict that the back of our skulls will extend/grow anteriorly. (means behind us). No one can know for sure what forms of evolution will truely take place. The has also been theories about technology. Apparently it exsists right now, machinery that can send out electrical signals to the brain wirelessly to one of your lobes. It has been tested in New York City and a few other states or countries i believe. Imagine years from now, people will no longer have to carry a cellphone. Pretty neat eh.