[PVE] Group finder / Raid finder! Awesome feature in WOW and I have been told it's in DC Universe as well. Sign-up, healer, tank, DPS... done! It works so well! [LFG] Sanctum... crickets -_- (include an AA check box. For example: Assassin signs up for a Godslayer RoF, they also check FH or not perhaps?)
[PVE] Content! More quests, an expansion would be nice. Dailies? I've been doing Khitai faction quests as dailies, but it's played to death, need some new solo PVE content; and challenging at that! Story, chain quests, maybe something to solve?
[PVE] Update quests to reflect the current state of the game. In looking for unplayed content I did the guild renown stuff. While I found the quest, Howls in the Wind, fun for the hour it took, I dropped it once I was asked to shell out 200 gold! Hmm, the one in the store comes with armor?
[PVE] Maybe consider making old world content group quests solo. WoW also did this to get more playability out of existing content, I think it came with the Lich King Exp. Point is group area quests pretty much Thunder River and maybe even Kheshatta, everything thing those level and below should be evaluated and changed to solo play. Content and quests is what interests me, grinding rares... nope.
[PVE] Places to explore! Stuff to find without an NPC putting an X on the map. Like Xan's Bounty on White Sands.
[PVE] Ability to active low level quest exclamation marks!!! Finding NPCs which have quests I missed during leveling is not what I mean by exploring and finding stuff! Granted it entails much of what's available, so I do it anyway.
[Crafting] More professions! Even if it's just fun stuff without end game in mind, WoW's Archaeology springs to mind. Seriously, from an MMO view that game has so much to offer even after, or once, you've hit end game raids.
[PVP] Since I'm on the WoW thing (sorry), Alterac Valley! Raid PvP, outside of a siege. I've spent entire weekends playing AV.
[Items/Interface] Vanity gear... It's really nice to have tones of options to dress up a toon, but all that takes space (another major issue in AoC, although I hear there might be more room on the horizon). Anyway, it would be cool if vanity gear was setup like TSW, no inventory space just a menu system -IE a wardrobe. So in game, perhaps we could have an option to add something to vanity; the useful armament would be removed from your inventory and that would unlock the vanity garment in the wardrobe menu.