/agree with bringing back some of the old lore.
I always wondered what happened to Mistmoore, and I'd like to see something happen with th alliance between the dark elves and Crushbone.
A couple more ldon themes would be nice (I'd like to see gnolls personally, Qeynos is an old world zone all should be able to get to). Also a few new items should be trickling in. Give people a reason to keep doing these.
Loot in some zones needs looked at. I'll use Hate's Fury as an example of a zone where noone went to even when it was a bonus zone. The required level on the stuff is too high to compete with other, easier to get stuff.
Npcs added to all cities similar to those of the froglok starting city that cast low level buffs on newbies.
Give titles for doing some of the older quests to encourage people to get out in those older zones and give them a shot. The Qeynos Badge comes to mind as a quest I actually liked.
Continue the newbie quest in Shar Vahl that is about the whisperlings. I always wanted to know more about it

Expanded tinkered items. For example I'd like to see a tinkered "teleportation device" similar to a gate potion in difficulty and cost to make. Other cool things could be a one time summoned pet (tinkered spider?), something that has a voice graft effect, maybe a very minor healing ward (make it do less the the first level of the aa one). I dunno I'd just like to see more neat gadgets, plus with the new augs poisonmaking and alchemy got a big boost so I think it would be fair.
More transforming weapons like those gauntlets from Chardok.
I dunno what else. I will think on it.