Original
We are farming ascalonian Catacombs in under 25min a run now, here is some tips out their to help people who are still struggling. Most of these tips will involve you being an active and vocal leader if you want to co-ordinate them in a pug, pugs are only as good as the leader, if you want a good pug lead it yourself, and make VOIP mandatory.
Party Comp
If possible have protection and regeneration with full uptime, a banner warrior + hammer guardian can handle this. These 2 buffs combined with decent defensive stats allow you to facetank most mobs in the dungeon with little threat.
Kholer
Dodge the pull, it has an obvious windup animation now so its cake compared to beta.
Keep him perma crippled and make sure to keep one dodge free at all times to deal with the pull, a warrior with mace/sword can facetank him pretty easily using the multiple blocks and dodges, kholer seems to like sticking on melee range targets if you give him the oppertunity.
Scepter Route
Protecting the NPC
There are 2 seperate chains of burrows, both are 3 long. The burrow to the west of the room which spawns a breeder is the easiest starting chain. We had myself a hammer warrior get this burrow low as well as the breeder, then just kite it about while keeping the small add numbers down as low as possible. The rest of the party would zerg the east chain, the veteran mobs will respawn if you kill them while their burrow is still up, you need to get both the mob and the burrow low, then kill both in quick sucession. Killing the burrow too quickly will trigger the next burrow and you will end up with an extra veteran mob to deal with. Once the east chain is complete, we done the last 3 burrows as a 5man and finished the encounter. The biggest mistakes groups make on this is not killing the burrow and graveling at the same time, and triggering both routes at once, both of those mistakes makes it much harder than it needs to be.
Getting the scepter pieces
This is pretty easy, the pieces are lying about the room and the mobs will disapear when you hand all 5 to the npc. run about as a 5man and grab each piece while kiting the mobs, there is no reason to fight them. Once you get all 5 run back to the NPC and it will despawn the gravelings that are chasing you about.
Howling King
Stay close to him so that you can dodge his scream, its does silly damage and stacks confusion on you. Taking even a few ticks will kill even the tankiest player. It has a very wide cone so you want to dodge to his rear instead of sidewards. If your party has enough CC, spam it all when he starts summoning mobs since it can get you overran with veteran gravelings if you allow it to channel for too long.
Ghost Eater Route
Trap Encounter
Have 3 party members on the 5 traps and your 2 tankiest members with the most control down in the trap area. All you need to do is run about and survive inside the trap area while the traps kill the mobs, skills such as Line of Warding are amazing here since you can make a wall to keep the mobs inside the traps.
Building the Mortars
This is one of the more difficult encounters, best way to do this is to have a kill priority, we use Ele>necro>ranger>warrior>mesmer>monk. Thats about all i can say, use line of sight if you can and try to kite the warriors while killing the more dangerous ranged mobs.
Ghost Eater
Pretty easy, just kill him and interrupt the channeled skill so you don't get overran with the little ghost oozes. He's by far the easiest of the end bosses.
Torches route
Lover's room gravelings
This is quick tricky the way to do this is to burn the burrows down as fast as possible and move on the next, kite any remaining mobs from the previous burrows over to the next and try to damage them with aoe and cleaves. If some small gravelings get onto the event items, one hit will aggro them onto you which is all that is needed.
Burrow clearing event
Easy one, just go from burrow to burrow killing them, have one player on "interrupt the breeder" duty, a hammer warrior is excellent for this since you have 2 aoe inturrupts and 1 single target one, all on one weapon, then you have second-set interrupts as well.
Collosus Rumblus
Dodge the red circles, stay as close to him as possible to make dodging the scream easier. The scream has over 180º cone so if your not behind him you will pretty much die. Apart from this it is a cake boss, a good tactic is to allow his channeled "rumble" to go full duration, it makes rocks fall down but they are far easier to dodge than his normal melee and scream.
End notes
I hope this was helpful, one thing to keep in mind is that glass cannon specs are not really that strong, the loss of uptime due to having to back out of combat often makes you do less damage than if you had full uptime as a tankier spec. The more aoe healing the better, we had a shout heal warrior, a banner regen warrior and occasional guardian/ele aoe heals. This crazy regen in combination with high vit/toughness and protection+occasional aegis turned our group from barely surviving this run to farming it in 20minutes, that's the difference that swapping a mesmer for a guardian made for our runs. Ofcourse I am not saying mesmers are a bad class, I am sure they will fit into certain groups well, their boon strip and feedback abilities are very usefull on certain fights especially mobs which cast aoe projectils that are reflectable. Just that we lacked protection and a guardian fit that role for us.