World of Warcraft Patch 4.0.1 is now live, and we've compiled all the major changes in one handy guide.

UPDATE: The maintenance is complete! Enjoy patch 4.0.1!

As you may have heard, patch 4.0.1 will go live today in World of Warcraft following the extended maintenance, which is scheduled to end at 12:01 p.m. PDT. Blizzard recommends that you turn on your background downloader, and we have to agree. Once you apply the patch, it could take up to an hour to install, and then you'll need to download around 1.2 GB using the new streaming launcher.

Keep reading after the jump for a rundown of the major changes coming in patch 4.0.1, as well as the patch notes. Remember, this update paves the way for the launch of Cataclysm on December 7.

• The streaming launcher lets you play while you download.
• Major class changes include the switch from mana to focus for hunters, a tanking tree for death knights, and a soul shard update for warlocks. Also, ammo has been removed from the game and all talent trees have been drastically condensed.
• The glyph system has been overhauled to add a new glyph tier and a revamped user interface.
• PvE/PvP currency has been converted to Honor/Justice Points and gold.
• Bosses and daily dungeons now award Justice and Valor Points.
• The Flexible Raid Lock System debuts in Icecrown Citadel and The Ruby Sanctum.
• The guild cap is now 1,000 members.
• The reforging system lets you customize the stats on your gear.
• Stats have drastically changed. For example, Spell Ranks and Weapon Skill have been removed from the game.
• Guilds now have their own revamped interface that adds a wealth of new features, such as the ability to view and search the professions of guild members.
• Gems changes will include color switches and stat conversions.
• Arena Season 8 has ended.

The full patch notes can be found on the next page.