I haven't personally done AQ40 but I talked with members from a guild who ran it a bit in order to practise for Kronos AQ launch and since AQ launched and they haven't reported their findings, I'll list here what I can remember from our discussions:
Emperor Vek'nilash hits too much. He was supposedly 1-shotting tanks such that the guild had to use level 70 tank and after trying it on GM account, he indeed hit 10k Unbalancing Strikes (wearing T6, although scaling is such that the damage of course wouldn't be much different at level 60), about as much health of an appropriately geared level 60 tank. I'm not in mood for estimating his unmitigated damage from retail videos I found (like this one, presumably a reupload of retail vanilla kill) but the damage is clearly far lower.
I remember one of the guys saying there was an encounter in which adds spawning somewhere in the room didn't aggro and could be safely ignored. However, I can't confirm this testing this solo.
While trying to confirm the previous point, I noticed Fankriss the Unyielding could be disarmed (the Hatchlings and Fangs aggro just fine, though). Clearly shouldn't be the case, it's probably worth investigating if this applies to a variety of mobs that don't use weapons.
Since #415 is closed, I'm opening this issue.
I haven't personally done AQ40 but I talked with members from a guild who ran it a bit in order to practise for Kronos AQ launch and since AQ launched and they haven't reported their findings, I'll list here what I can remember from our discussions: