So, here is my suggestion for the future:
Dedicate an update to redesigning new version of the old Ebberon raid loot and epic items. The code is already there, for the most part, so all that is needed is to copy/paste and tweak the stats and requirements of most of these items so they are relevant. Then, add a new difficulty setting separate from the N/H/E/EN/EH/EE system called Legendary. It is only available to toons who have completed the EE (or Elite on non-epic raids) on a quest/raid at least once.
Legendary will be balanced for ML30+ toons, so that when the level cap is raised towards the end of next year, it will still pose a challenge. Completing Legendary difficulty quests will have a chance to drop these new versions of the previously ML20 epic items, which will be BTC on acquire (to keep people from buying their way to the top again -- less short-term gain, yes, but much better long-term gain because it keeps people playing and paying for MUCH longer) and require ML28 to equip (or ML30 if it is released after the new level cap takes effect).
Perhaps, to make such an encompassing update more manageable, it should be broken down into chunks. Desert could be redone in one update, then Marketplace in the next, etc. However is best according to the devs' judgment.
It would be retreading old ground, in a way, by essentially re-releasing "Epic" settings of old content... But it would make it worth farming that stuff again. It would breathe a tremendous amount of life into the game, and give people something to work towards again. People need a GOAL at the end of the game, some reason to do TRs, some reason to grind quests. And it wouldn't necessarily involve creating NEW content either-- just modifying the stats/damage of mobs and traps, perhaps throwing in a few new tricks for some bosses, and changing items that already exist to be better. Essentially, it would be like Epic Gianthold. But I would be okay with that, and I'm sure many others would be too.
And heck, the devs could package them as entirely new packs if they wanted. "Buy Legendary Devil Invasion -- Includes redesigned, re-envisioned versions of Devil Assault, Chronoscope, Voice of Destruction, Hound of Xoriat, and the Subterrean Explorer Area, with incredible new and powerful loot to be excavated: ALL for just 595 points!"