DM's, watch how you run this encounter or you might end up with a TPK. Make sure you know what your party is capable of before running this one.
I ran this encounter with the dracolich last week and almost had a TPK. The dracolich's parayzing gaze attack and the paralysis from his natural weapon attacks, both with a Fortitude DC 26, make him nearly unstoppable. I had 3 of the 4 party members plus the cohort paralyzed within 4 rounds when I decided to fudge things a little bit and shorten the duration of the paralysis. I didn't want to end the AP right there so I let them have a little easier of a time. Fetor was in on the fight too, after having fled from them earlier and the party spent too much time focusing on him rather than the dracolich.
My party has no powerful arcane caster, so they had no access to flying magic, and although they do have two combat monsters with high Fortitude saves, that DC 26 is a hard one to make.
When I ran the room three PCs died (or were paralized) almost instantly. The rouge tumbled into the room and took a full attack from the dragolich on the first round. It also didn't help that Fetor had been working his way towards the final room after the deminsion door to his 'bedroom.'
Anyways the monk grabbed the main fighter's body (he was the leader) and started running down the hall. The cleric was still halfway through the hall (taking his time due to the latices). Fetor, still alive, casts his last lighting bolt down the hall, killing the dwarf. The monk's evasion made him the only survivor.
The monk took the fighter to the church where he had prepaid for a reserection. Since the party used the moneychanger in town as a bank, the leader was needed for the monk to get his share back. After that the monk quit due to a 'bad party.' Everyone else made new PCs at the same level as the fighter and I had to run a side quest for them to regain a level. Afterwards the reentered and fought their way through a restocked dungeon and killed the dracolich they were prepared for.