The talent calculator now uses the WoW: Forever talent trees from game build 1.60.1.70707. Until now it showed the Classic Era layout that the client still carries in its old talent table; the trees players see in Forever are stored separately.
All nine classes now have their Forever talents: 464 in total, with rank values for every rank, new talents such as Gore Drinker, Lingering Rage or Shifting Power, and the talents removed in Forever taken out.
Each class page lists what changed compared with Classic Era: new, removed and moved talents, changed requirements and changed rank values.
The new Patch notes section collects Blizzard's official WoW: Forever change lists with links to the source posts, and each class page shows the official changes for that class.
Sources: