Blizzard QA Hortus has come out with an updated issues list for the World of Warcraft Public Test Realm. If you're running the PTR client, it would be advisable to go over this list so you don't end up wasting time reporting what the developers already know.

Most of the reported bugs seem to involve problems with the user interface although there are also quite a number of problems with both the NPCs and the World Environment. Here's the complete list of known issues taken verbatim from Hortus' post:

UI

• The combat log will rise vertically on its own.
• Raid and Battleground chat are not enabled by default in the general chat window.
• Battleground and arena warning messages are not appearing.
• Using an instant ability after Steady Shot can lock out the use of Auto Shot.
• Sometimes when Master Loot is enabled with a threshold above uncommon the Master Looter still has to assign uncommon Bind on Pickup loot.
• Players are initially unable to loot any Bind on Pickup items with Master Loot on.
• Yells sent by NPC's are not showing up in the general chat log.

• Shattrath City Peacekeepers and Scryer Vault Guardians are missing from Shattrath City.
• Gear conversion NPCs in Quel’danas are not fully implemented.
• Madrigosa's flight path outside the Sunwell Plateau has unnatural movements.
• The Hellfire Channelers in the Magtheridon encounter are not resetting properly.

• There are chunks of water missing all over Outlands.
• Jumping onto an elevator can cause disconnection, crashes or falling through the world.
• After attempting to zone into Heroic Magister's Terrace without having completed the quest Hard to Kill, you can't enter the dungeon even after you changed dungeon difficulty to normal.

• Mac OSX 10.5 is not playing back audible sounds over voice chat.