I, personally, won't be back with any seriousness until the alignment of the NPCs is enforced to the same stringency as it is against the PCs. I.E., griffons being employed by and acting in defense of dark-grey/diabolic characters is NOT okay, particularly against light aura'd PCs.
In general, though, to enhance accessibility and enjoyment of the game for most people, I'd say the following should happen:
1. Content balancing. This is a builder-level issue. Areas with overly-obscure/impossible-without-ooc-info quests and access points need to be redone to be accessible to a broader population of the game. New players are more often hooked by the metaworld, exploration, and pve. Improving the accessibility of that side of the game is critical to improving the retention and enjoyment of new players. Older players may be drawn back to areas by the prospect of not having to hit their heads against a wall (or resort to what is effectively cheating) to access and best that content.
More in this regard: sensible building choices. Stupid levels of immunities to damage types, spell immunities, glow scripts that spam one-shot abilities, instakill scripts that are unavoidable, and lvl 51 random encounter NPCs that spawn with these things (or natural reach, or kipping/bashing/charming/glowing nonsense) in numbers exceeding 1 is not okay. Those NPCs and areas currently swarmed by this nonsense need to be toned down. It is NOT fun to spend 6 hours trying to recover because one failed attempt caused an entire group wipe, and everyone's naked and trying to get back to their crap. Less no-recall zones as well.
2. Non-class, non-race, non-alignment specific personalization options for characters purchased with LPs and trained with enlight-earned XPs at GM. A few examples of this would be access to certain skills or spells (perhaps new ones created just for this purpose), or specific enhancements (only one of which could apply at a time). Just off the top of my head, the kind of enhancement I'd personally like to see would be a colored aura that would provide a bonus to a specific save or stat that appears in the short desc of the PC and strengthens as the skill masters.
Example wrote:
Training a blue aura would provide a scaling bonus to Willpower saves.
At Poor to Fair it would look like this:
(Weak Aura) A willful male human is here.
And provide a small bonus to will saves.
At Good to Superb it would look like this:
(Aura) A willful male human is here.
And provide a moderate bonus to will saves.
At Mastered it would look like this:
(Strong Aura) A willful male human is here.
And provide a large bonus to will saves.
Possible aura bonuses would include
willpower,
fortitude,
reflex,
art,
mana,
moves, and
HP.
Other possible bonuses include a purchase-able one point increase to a specific racial max on a stat (again, with only one being possible to have active at any one time).
3. Multiclassing. Armor restricted to lightest of selected classes (i.e., a merc/sorc would still take spell casting penalties for gearing up in addy). Each status gets dedicated to a specific class (to a maximum of 2). I.E., Mr. Mercsorc started as an amateur mercenary. He reaches level 5, gains enough exp to train level again. Instead of typing just train level, he types train level sorcerer. He then gets a level in Sorcerer (with the appropriate HP/mana/move gain of the Sorcerer class at each of the novice levels). Mr. Mercsorc cannot train mercenary skills during his Novice status. Instead, he gets access to Sorc skills and spells at the Novice rank. If, at Apprentice, he types train level mercenary, his Apprentice status will be dedicated to merc skills (with all the appropriate stat increases for merc leveling throughout Apprentice).
This would probably require a refactoring of what statuses certain class-specific skills and spells become accessible to balance the multiclassed characters, as well as to force real choices between which class to train at which status. All alignment-based class restrictions would still apply, of course, and no LP class options would be available for the secondary class (no griffon rogue/mercs, for example). This wouldn't be a means to get a barb/necro griffon, or a paladin/hellion combo.
4. Bring back lvl 51 heroes and amulets. Monthly tournaments for two classes (schedule them for the same weekend to help dissuade players from stacking multiple hero characters).
That's all that comes to mind at the moment. Might come up with something more later.