One of the big changes for this BWE is the inclusion of dedicated French and German servers. A number of the European servers have been marked specifically for French and German, two of the officially supported languages. New players will be able to pick any of the 96 servers (that's 48 US-based servers and 48 European) to be their home world. Players from the previous BWE will have a 30-hour window from 3:00 p.m. EDT on Friday to 9:00 p.m. EDT on Saturday during which they can transfer between worlds without spending any gems. After that time-frame, transfers will cost the normal 1,800 gems. Each account will be credited with 500 free gems automatically. Players will also be able to get an additional 2,000 gems; you won't actually be charged for the transaction, but you'll have to enter valid credit card details in the Gem Store.
Check out the exhaustive server list on the the official post.