A new dev diary from the team goes through the lengthy explanation of how sector space will function after the next big update. Instead of having several galactic zones, the new map will have three large areas: alpha, beta, and delta quadrants.
The team reorganized over 350 systems to fit with the new map and even added a few new systems (such as Tellar, Trill, and Betazed) for Foundry use and future content expansion. Astrometrics has received an overhaul, and players will experience stars and planets on the map that are significantly bigger than their ship in order to give the impression of true size.
[Source: Dev diary. Thanks to Michael for the tip!]