Blizzard just sent out some additional information via email to their subscribers about the new instance of Ulduar. Not only are they addressing the dungeon itself, but they have headlined the Tier-8 armor sets, Dual Specialization and many other features in this huge patch we are all waiting for.

Taken directly from the official "Under Development" section at the Blizzard site, you can read up on more of the lore and changes that are coming:

"My death...heralds the end of this world."
-Loken, fallen lord of the Halls of Lightning

With the upcoming release of the next major content update for World of Warcraft, Ulduar's gates will swing open, allowing heroes of the Horde and the Alliance to venture into the titan Pantheon's ancient halls. In addition to an all-new raid dungeon, this content patch will introduce the dual-talent specialization system, new quest lines, and the epic tier-8 armor sets.

To whet your appetite for the adventures to come, the Insider offers this overview of the new features awaiting you. Read on, but be warned: of all of Ulduar's secrets, perhaps the most ominous is that the temple's vaulted walls were built not to keep intruders out, but rather to keep something else contained within. Above all else, Ulduar is a prison restraining an ancient evil.