Guild Wars 2 - A condensed list of HoT features by halycon8

• 4 maps, some containing 3 "biomes" - all containing many new events
• New races of npcs and monsters
• Repeatable adventures with leaderboards
• Map bonus reward system
• 1 profession
• 9 specializations
• New Personal Story
• Living World releases including Living Story S3
• 2 new armor sets per weight (from the open world)
• 5 weapon sets
• Legendary armor
• New legendary weapon set
• Legendary back pieces
• 60 new item skins, miniatures and more
• 7 mastery tracks with 39 tiers
• Precursor crafting
• 1 raid with 3 wings
• 2 Guild Halls with 6 core buildings and over 175 decorations including a customizable PvP arena
• New guild armor and weapon sets
• New PvP gamemode with new map
• Guild teams and leaderboards
• PvP leagues
• 10 New PvP reward tracks
• New WvW borderland
• New fractal system, rewards and 50 more levels
• Plenty of other smaller features and updates

SOURCE