Approx four or five years ago I had an accidental/random conversation with one of the prominent researchers at the Princeton facility (PPPL). Long to short, he said, "We're getting there. The more funding we have, the sooner we'll get there. But yeah, we're really close."
Mind you, that's what any research scientist would say. But everything I've seen and read since tells me he's was being honest and has been accurate. I hope he's right.