Today, the machines became a little smarter, as a computer named Elbot managed to achieve a 25% success rate when convincing a human being that they were talking to another human. via Gizmodo & The Telegraph
Should the law of exponential growth hold, it isn't going to long until we can create programs that can ace the turing test. Its taken 58 years  from its inception to this point, I don't think it will take us many more years before the test is passed.
Ray Kurzweil has previously stated in his books (Age of Spiritual Machines & The Singularity is Near) that we would be able to create a system that accurately simulates human interaction to pass the turing test  I think I am going to go out on a limb and say it will be much sooner.