More spells than are currently offered (at least more than the new ones in the spellfile), more thought put into quests (long, barely rewarding quests that have you grind x mob for y drop for hours are not fun, at all), a reason to gain faction beyond some incredibly outdated armor, a gate neck, or an underpowered augment.
The faction and quest issues can be rolled into one I suppose, but SoD has a lack of quests, nevermind ones that are actually fun. If Ikisith had some version of WoWs
Shattered Sun Offensive and
the Battle for Sun's Reach I would be a really happy camper. (WoW actually did faction grinding and rewards right)
Mainly though, I'd just like to see some awesome single group zones with scripted content.