I know we've got a lot of new content coming, but just wanted to share an idea for possible consideration some time in the future. I envision a "PvM Survival Mode" arena where a player or perhaps small team of players enters an enclosed space and faces waves of monsters that increase in difficulty/complexity with each successive round. For example: It begins with simple foes such as a mongbat for round one, then a headless one round 2, then zombie, skeleton, lizardman, ettin, troll, ogre, etc etc all the way up to Dragons, Balrons, Bosses, etc. There could also be groups of different monsters to make things more interesting: for example 50 mongbats all at once, a horde of orcs or undead, Lord British himself, or silly stuff like a barefisted Chuck Norris with 2000 strength. This type of gameplay element could involve many things, or be kept fairly simple. The arena could be a gold/plat/copper sink by requiring a modest participation fee to take on the challenge. Or it could be accessed with an instanced gate item (like an AMIB) or a public space with seating for spectators like the PvP arenas. There could be trophies for players who make it to level 100, 1/250 chance drops by special monsters, or simply no loot but a public leaderboard for bragging rights for the ultimate PvMers.
I ran this on a shard I was GM on, it was a very popular event. Plus we had leaderboards for fastest times and top leader got trophy to display at their house. If a time was beaten, the old trophy would disappear as the new top score was now the better time. The new best time had a named trophy of their own.