One of the biggest changes comes in the form of a 90 day log in time placed on all citizens of a city. If a citizen does not log into the game for 90 days, their character will be removed from the citizens list of the player city and their house will be eligible for pack up. On the bright side, this will allow city mayors to remove unused buildings and items from their city, should they be cluttering things up. On the down side, each character must be log in at least once each three months.
Past that change, other additions include a new guild master elections system, the ability of city vendors to wear bodysuits, a new 69 month veteran reward, and increased experience when in groups.
For the full list of changes in update 8, check out the patch notes over at the main Star Wars Galaxies forums.