Blizzard devs have released information about the upcoming v4.0.1 patch that will bring new framework to World of Warcraft in preparation for the release of the Cataclysm expansion. Called a "major patch", the core systems to be implemented include overhauled talent trees, an updated pet system, new Mastery stat, UI improvements, and the somewhat controversial PvP/PvE Currency System.

General

• Cataclysm Launcher Update
  • The new Cataclysm Launcher allows you to stream game data while you play. This will reduce the time you spend downloading, installing, and patching World of Warcraft. We'd like to get your feedback on the toolset and gameplay experience. Please head to the forums here for additional information.
• Reforging
  • Players can now visit special Reforging NPCs in capital cities located near Enchanting trainers. 40% of any one secondary stat on an item can be can be allocated to add a new secondary stat to the item. The stat being added cannot already exist on the item. An item cannot have more than one reforged stat at a time, though the Reforging of an item can be undone and changed.
• Copied Test Realm characters are not copied with their achievement history in order to better facilitate the character copy process.

Read the full PTS patch notes for v4.0.1 here.