This would be something I would be highly in favor of being added to GW's in the future. A PVE type ladder game and the ability to gain nice gear without having to "farm" so to speak. They would need to be hard like UW and FISSURE and quite unsoloable. There would need to be one setup though for "random pugs" so that people don't have to stand around waiting for someone to "pick me pick me pick me" or have TS/Vent required.
The mobs would be created within them according to the average level of the group and it would also take into account their "weapons" and their "armor" so that droknars runners wouldn't have any advantages. The mobs would equal their gear in weapons and armor plus a percentage better for the challenge affect since AI is not the perfect opponent. There would be choices for the group like "easy", "medium" "hard" and "Nightmare" and the harder the mission you pick the more XP and better loot that would drop. There would be collect missions, rescue missions, kill floozie missions, kill a certain number of mobs missions like LDON had and on a timed basis. You don't get forever to finish the mission, so it gives that adrinilin rush as players try to finish a mission before the timer runs out.
There would be a Priest at the beginning, so that if/when you die or you all die in a 2 minute rez cycle everyone can be rezzed over and over again. But, time is money and XP so the more you die the less chance you'll have of completing the mission just like LDON.
There would be "trapped" chests and desks and even doors, give the area a more RPG feel to it where one doesn't just rush through it but must be very careful each step of the way. There would be "alarms" that once a player triggered them, the whole area would come alive and looking for THEM instead of just standing and roaming in one area of the map. There would be puzzle mechanisms that one would have to figure out in a timely fashion, don't figure it out in time BOOM party is blasted and mobs appear from everywhere.

Of course new skills would need to be added to "detect traps" and "detect alarms" something rangers would enjoy I'm sure. Remove curses for the monks. Mezzers could get charm monster and during the encounter they could charm one monster to help them during the missions. Elementals could get familiars a little fire imp or something. Some of these skills that would be found in the LDON type missions on some boss perhaps that would need to be captured.

And at the very end of the deep dark dank dungeons in a far away place in a remote area protected by traps and alarms a huge chest full of goodies with at least 1 item for everyone in the group. Could have 1 gold, 2 purple, 2 blues and 2 whites.

There would be no bot farming since it would always require a group. Henchies an option if a way to program it without botting working for anyone.
Henchie groups though would never allow the player to reach the end game chest though, this would be for groups only.
One thing I would re-emphasize, there would need to be a random pug system for those that don't want to stand around or wait for a "pick me pick me pick me" type of play. That was the bad thing about LDON for Everquest, there was a lot of standing around waiting for someone to group with.