When the Model X was unveiled in February 2012, the expected delivery date was late 2013 and Tesla was going to build between 10,000 and 15,000 Model X units a year starting in 2014. Instead, the delivery date was pushed back and back for unspecified reasons, but the falcon-wing doors stood out as one of the likely problem areas. Musk later said that they were indeed a problem and, in May 2014, he said Model X deliveries would start in the second quarter of 2015. The company settled on a target date of the third quarter of 2015 late last year.
Yesterday, Musk said that X deliveries would begin in "probably about 3-4 months." Now that we're in this final stretch, Musk said he's looking at the various builds of the X every week and believes that the X will be a better SUV than the S is a sedan. He said that Tesla engineers have been working to get the falcon-wing doors, the rear seats and "a few other things that people aren't aware of" just right before building the production models. "Getting those final nuances right for the Model X is what we're focusing on right now," he said. Musk's comments on the Model X starts at 21:45 in the video here.
Speaking at the same meeting, Musk also sounded like he's ready to give up on battery swaps in the Model S, and that swapping is "unlikely to be something that's worth expanding in the future," which we take to mean we won't see it in the Model X this fall.