We did a couple instances over the weekend. The first was Ahn'kahet — impossible to spell and destined to be known as AK, I guess. It's definitely worth the visit, though it will take a bit more time than the early WotLK instances I've seen so far.
Ahn'kahet is found in western Dragonblight. It shares an entrance and meeting stone with Azjol-Nerub. It's another Nerubian Empire leftover, partially occupied by the Scourge and partly held by Twilight Cultists, who have also summoned some elementals. In other words, just about every type of CC is usable at one point or another in here.
The map is the longest I've seen yet in WotLK, and it's a bit more confusing; a couple times we found ourselves looking for the next hallway. At least one sequence requires you to deactivate two crystal orbs to free up a boss (Prince Taldaram). The complex map reminds me of Underbog a bit, with a winding multilevel path. As with Azjol-Nerub, you'll have some 'paths' that are really ramps made of web; they're easy to miss.
Ahn'kahet has four bosses on Normal. None of them are a serious challenge per se but they all have tricks or complications that you should know about. With a good plan, things will go smoothly. Here are the key facts to know about each guy:
Elder Nadox - Nerubian VizerThe first boss, a giant spider-looking guy, has one key fact you need to know. He'll summon adds during the fight. Most of these are pretty unimportant, but you absolutely must keep track when he summons a Ahn'kahar Guardian. While these guys are up, Nadox and his summons are immune to damage.
You'll get a raid warning when a guardian is summoned; pay attention and burn it down. If you do, the fight will go quickly.
Prince Taldaram - DarkfallenAs I mentioned, you first need to release this guy before you can fight him. Look for two pillars, accessible via web ramps. Each pillar will have a small party of mobs and a crystal orb. Kill the mobs, click the orbs, release the boss.
Taldaram himself isn't too tough of a fight. He'll spawn Flame Spheres, which do damage to nearby party members, but on Normal the damage isn't too bad. He also does a Vampiric Embrace on a party member, which is a bit annoying... but the right answer is to DPS his butt (which ends the Embrace), so no need to adjust. Avoid the Spheres and burn him down.
Jedoga Shadowseeker - Twilight CultistYou'll eventually come to a room with Twilight Cultists and two stairways. Take either one (doesn't matter) and you'll see Jedoga floating amidst her initiates. When you kill off the last initiate, she descends and starts the fight. When she starts the fight, she'll summon more initiates, but they'll be inactive and untargetable at the start of the fight.
Mostly, the fight isn't too complicated. She does an AoE that you can avoid if you're watching. But there's an important event to watch for. A few times during the fight, Jedoga will ascend and become untargetable, calling for a volunteer. One of the surrounding initiates will step forward, walking towards her circle. Kill it quickly. If the volunteer reaches Jedoga, it will sacrifice itself. This adds its health to Jedoga, but more importantly gives her a +200% damage buff. That hurts, and even on normal a couple of these will likely lead to a wipe. So find and kill the volunteer!
Herald Volazj - Faceless OneThis is a fun fight! He's not too bad on Normal; he hits a little hard but nothing that should trouble you. The key is the Insanity phase. You'll see this twice, when he hits 66% and 33% health. Everyone will phase out and see shadow-copies of the rest of your party. Kill 'em. They're not too bad — they're not full copies of your party, and don't have all abilities. Once you've killed them, you'll see your other (real) party members and their shadow-copies, so you can help kill them too. Do that quickly, and you should have no trouble with Volazj.
Any of these bosses can wipe you if you ignore the tricks, but if you know what's going on, they will be pretty easy. The scary part? There are Heroic achievements for killing the bosses... while basically ignoring the tricks. (See Respect Your Elders and Volunteer Work.) These will be pretty tough, but I guess that's what the achievements are for!