As Matt Rossi is analyzing in more detail, the attunement requirement for Karazhan has been removed, although at least one person in the raid does need to have the key to get in the door. How do we know? New patch notes.
Here, in full, is everything that's changed in the latest iteration of Blizzard's official test realm patch notes, brought to you, as always, by the power of diff. Much of this has been covered on WoW Insider already, because Blizzard is slow to update the patch notes; the stuff that looks new to me is in bold (which in this particular case is only that the new Mortal Strike-esque effect on Flametongue Weapon applies to Flametongue Totem as well).
- Removed: "The benefits of drinking out of combat have been delayed. It will now take five seconds before the full benefit of the mana regeneration will come into effect." (now restricted to arenas only)
- [Druid] Lifebloom will no longer cause error messages when interacting with Spellsteal or while the Druid is under the effects of a Mind Control.
- Improved Blink: This talent no longer reduces the mana cost of Blink. Instead, it increases the chance for all attacks to miss the Mage by 25% for 2/4 sec after Blink is cast.
- Icy Veins no longer stacks with Power Infusion (as well as Bloodlust/Heroism from the last patch notes)
- Mana Shield: This spell will now get a percentage of the Mage's bonus to spell damage as an additional effect.