Xi'an is opening at 67 Bayard St., supposedly in the next month. I think this is the old Moon House/Shanghai Kitchen location, which was closed, though I hadn't noticed any activity inside. This makes sense since the existing location is located off the beaten path for a good portion of their targeted clientele, plus only has room for about four customers at a time (or three large customers). The new space has room for 30.
Xi'an Famous Foods
67 Bayard St, New York, NY 10013