http://forums.wow-europe.com/thread.htm ... 9901&sid=1
Some new info, especially about the new instance "heroic" settings:
Heroic Dungeon-Difficulty Feature
Another exciting aspect of the expansion is the new Heroic dungeon-difficulty feature, which will let you experience many of the expansion dungeons in two different modes. One mode will be the normal version, and the second mode, Heroic, will boost the difficulty of the dungeon. The additional risks that players take on at the higher difficulty setting will also come with the opportunity to gain greater rewards.
The challenges that await players inside of a dungeon set to Heroic difficulty will go beyond just increased hit points and attack power for the creatures inside. Enemies will also have extra abilities, making each encounter more tactically challenging. The rewards of course will scale up accordingly with the boost in difficulty. In order to unlock the Heroic level of a dungeon, players will need to be level 70 and achieve other objectives as well. More details on these prerequisites will be revealed at a later date.
While I'm on the topic of dungeons, I wanted to mention here that the Black Temple -- the dungeon intended to offer the most challenging encounters in the game -- is still deep in development and will be opened up for public testing after the expansion is released. It's important to us to spend as much time as possible balancing and polishing the content in this dungeon before releasing it to players; it's definitely not something we want to rush out the door just for the sake of meeting a deadline. We look forward to sharing more information and offering some glimpses of the Black Temple content in the weeks ahead!and then opening it up to Burning Crusade players on the test realms once they've had a chance to level to 70 and gear up in the other dungeons.