TBS:Overview

Content -- About a dozen new zones to explore targeted at players level 65 and up. This is definitely a high-level only with most content for players in the 70-75 range.
Fellowships -- Create a fellowship with up to 9 members. When 3 or more fellowship members are in the same spot in a zone they can create a campsite which allows members to teleport directly to them. Campsites can also be created with powerful effects.
Guild Banners -- Similar to fellowships, a guild banner can be planted by a guild leader whenver 18 or more raid members are present. Later comers to the raid can teleport directly to the banner which can also have effects applied to it.
Missions -- Complete Pirate or Combine group missions and purchase quality armor and weapons. There's around 60 or so missions with varying difficulty levels in the expansion.
Raid - Survive through what will be the hardest raid content yet. Raid rewards will come through a vendor system with points dropped during a raid with which players can buy various levels of raid gear with.