Dragonspear Castle is being worked on by tfunke, and should be in game soonish from what I understand. Dragonspear is one of the more exciting places in the region so I'm personally eagerly awaiting for it to appear. From what I saw the castle will be CR9.
I have spoken to several people lately, and the general consensus seems to be that there is a lack of epic dungeons. So here's what I propose:
A portal can be placed in Dragonspear which is active and connects to one of the nine hells. Beyond the portal lies a truly epic dungeon (it's one of the hells after all). It should be filled with various outsiders, several "mini bosses" and the main boss, probably a pit fiend (yes, yes, we already have two

). The pit fiend should be a named one, and have personality (through his battle dialogue or something similar), it should also be in the range of the white dragon in difficulty. Once a group slays the pit fiend, the portal in Dragonspear is closed for a time. Let's say an hour? Two maybe? A reset cycle? Not sure which would be most fitting. I would also probably make it so that the portal can't be accessed unless you have at least 5+ people in your group, this should prompt people to spend time seeking others out even if they are playing a pb which can clear half the "dungeon" on its own. Also, if more groups gather for it, they can do it together since this shouldn't really be about xp but rather about epic (cr30+) content. Maybe the pit fiend can give a lot of xp to everyone present (~1k) regardless of numbers? I'm not sure if that can be done.
Thoughts? Would one of our dear world-builders be interested in making something like this (tfunke)?