The current update I feel changes the incentive to run dungeons. As such I suggest altering the manner in which the rewards are doled out to give those who want to farm the opportunity to do so but in a way that will require time and effort.
To receive your dungeon completion rewards you need to open the end chest by using a key for that chest. The key is earned when you have killed a set percentage of all XP generating mobs in the path. Mobs that do not generate XP, like gravelings in Ascalonian Catacombs, do not count towards this total. There are multiple tiers for each path and dungeon. Keys are like tokens, they are persistent and are placed in the Wallet next to the token number for the particular dungeon. IE – a XXXX / YYYY format, X being the standard token we all know and love, and Y being the new keys.
When you enter, lets say Ascalonian Catacombs Path 3, the UI of the dungeon will have changed. They will include a notation showing which tier of the extermination you are on and how much out of how many, IE – Tier 2 of 3 – 70 out of 140 Remaining. Similar to what you have in your Daily. Upon completion of the tier of a bonus chest appears as per completion of daily. The chest will contain a key per tier plus an additional key for completing all of the tiers. So if there is 3 tiers you will get 4 keys. The keys will grant you regular dungeons rewards as per the current system. You will only receive the bonus dungeon reward when you open the chest for the first time.
Should you complete the dungeon before finishing the tier you get the dungeon completion for the achievement listing, daily, and monthly. Additionally any normal mob drops you get you will receive as per normal. Upon completing the dungeons all remaining mobs will have their XP value set to 0.
As for bonus events, I believe they should include a low chance to generate a key upon completion.
As an addition to the chest include a low chance to get a unique skin from that dungeon. 6 armor pieces for each of the 3 armor classes and 5 weapons (23 total unique skins) per dungeon. When you have completed the set from a dungeon you automatically receive a few more dungeon tokens each time.
The chest always appears after you kill the dungeon boss. If you have keys, from that run or prior runs, you can always open it. IE last month I did AC path 3, got 3 keys. Now I did a quick run of AC 1 today got 0 keys. I can open the chest 3 times.
To cover some key points that I feel will be brought up as questions.
Keys are tied to a dungeon, not a path. So yes you can keep farming an easy dungeon path and getting keys. You can get multiple keys per run in a dungeon. The number of the keys I feel are best left up to ANet, so that the easiest of dungeons can get 2 keys, while harder and harder can get 3,4, and honestly I feel that Arah for kill count should be 5+ (some paths have easily hundreds of mobs).
The chest always appears after you kill the dungeon boss. If you have keys, from that run or prior runs, you can always open it. IE last month I did AC path 3, got 3 keys. Now I did a quick run of AC 1 today got 0 keys. I can open the chest 3 times.