
Group configuration:
You need either a tank that has AoE threat generation, or a single-target tank and a very high-level dps.
Someone who can inititate fellowship manoevers may also be required.
Don't let the trash fool you: the end boss is very difficult compared to the trash (the trash is cake; the end boss is a bit tough).
The majority of the instance is very easy, and linear. The only note: clear all side rooms! The mobs call for help, and they can be heard over large distances. If you don't clear side areas before engaging the next pull, you WILL clear them on that pull.

There is a particular mob that has to be killed first, or it will run around aggroing other groups. I can't recall the name, but I'll update the next time I'm in there. You don't see this mob until your first big room of the instance.
In one 'straight' passage, there's a cool cave-in effect to force you to go another way.
When you turn in the quest to the blue chick deep inside, she directs you into a hidden passage behind a waterfall. If you die and forget, it's to the right, with a left after you go under the fall.
After the waterfall, you do have a drop you have to make. It's not far.
Final boss fight
There's another drop before the final boss. If you run off the edge, you will not take damage. If you just drop off the edge, you will get lamed. Recommend running off.
The final fight in the instance starts with ... Crackbone? I forget his name. You get him to about 20% health (estimating here), he goes and wakes the big turtle. The turtle eats him, and now YOU have to fight the turtle!
Turtle abilities:
little turtle adds: smaller turtles join the fight periodically. This is where you need an AoE threat tank. If you don't have one, have a level 60 or so dps kill the ones on the healer. They can stun, so it's imperative to keep them off the healer.
knockback: anyone in the 180 degree arc in front of the turtle will periodically get knocked back. dps need to stay behind the boss.
dot effect: not sure what this was, but it also seems to be limited to the 180 degree arc in front of the turtle. It's a steady damage over time.
Strategy:
The first guy is plain tank-n-spank down to 20%. You have a breather while he wakes the turtle, but you do NOT go out of combat.
The tank should grab the turtle and run to the right, putting his back to the big stone there, to stop him from moving on the knockbacks.
The dps should run LEFT, to get behind the turtle. Casters and healers should go with the dps.
As soon as everyone is in place, initiate a fellowship move, and everyone pick YELLOW (damage over time). You *need* the extra damage to bring the turtle down, and the dot will keep ticking, even if something goes wrong, and your dps get knocked back. Our first time getting this, we lost the tank, and the dps were able to finish him off.
Unless they are eating the healer, ignore the spare turtles. Killing them will just cause more to spawn, and you are in a dps race against the big turtle. When it dies, all the small ones vanish.
More info next time we run it again...
In other words forget it! We gave it a good shot.