Welcome to the Cataclysm beta test. Throughout this test period, we will deploy fixes and improvements to the Cataclysm test environment and provide information and updates in this thread.
At this time, the following are unavailable for testing in the Cataclysm beta:

Reforging
Archaeology
Goblins and Worgen Races
Transmogrification
Guild system updates
Leveling past 80
Endgame dungeons
Dungeon Journal
Tol Barad
Character info screen updates

We’re currently tracking the following Known Issues:

Testers may receive a Lua error relating to Blizzard_SettingsDefinitions_Frame_Classic.toc when logging into the game.
The World map has some selection and highlight issues.
There may be a LUA error when opening the Collections UI or selecting a new pet or mount.
Minimaps are not working inside a majority of the indoor environments.
The Mastery Passive and Armor Specialization can’t be learned from your trainer.
Leveling up shows “Congratulations, you have reached [Level 0]” in the chat.
Some questgivers in Southern Barrens aren’t spawning in properly.
Some quest NPCs in Redridge Mountains are not spawning in properly.