I just finished the systems class at XJT last week. At the end of the course, a Staffing manager came in and said that they can't say with any degree of certainty where new hires will end up. He showed us a chart which indicated that some new hires are going to every base, with most out in LAX or ONT. Like SAAB mentioned, the staffing guy also said that there's so much movement right now that you could probably get the base of your choice after a few months.