Well, a post has been made with some explanations and cautionary info. (See DevTracker, top right of page.) Now we wait a few hours, or maybe a day or so, for the official or unofficial translations. There's no obvious start date. There are lists of most and least congested worlds, and some warnings about transferring to busy worlds (may increase world congestion), and stuff like gil limits, transferers may be prevented from logging in for several days while transfer happens, etc.