Sure, there's 'roleplaying', which most take to mean 'acting in the style of your character'. But even then, your options are limited. You could try to play a coward, but then you'd never take part in high-risk battles, and your effectiveness as a player would lead to people not wanting to play alongside you. Simple roleplay isn't what's missing.
I'd like to see the emotional richness and character observable in Second Life's social interactions combined with the rich combat system of World of Warcraft. This is not to say I haven't met some nice people in WoW, but our interactions have been limited to getting a particular task finished, after which time we part ways. I never know exactly if there's any deeper level to the exchange, as there's so little time to actually talk while questing.
Then there is guild interaction, some of which I know occurs well outside of actual gameplay. However, there's a sharp demarcation between 'being in-game and playing', and 'being in-game and socializing'. Given that the higher-level raids require a good deal of organization and strategy, it's unlikely you'll experience a deep level of socialization during that time. I'm sure many of you have bonded with your guildies, and have formed friendships with them, but that's just camaraderie, and that's not quite what I'm looking for here.
I think what I'm reaching toward is the concept of a player's personality being the key component of the success of a mission, rather than their function. Looked at a certain way, any combat encounter comes down to pure math. There are stats to concern yourself with, and precise timing, and a formula can be derived from the experience, to be applied in similar circumstances. And taken that way, it becomes clear that there is little in the way of unique human personality involved in this system. What is it that makes the difference?
When naysayers talk about games not being Art, this is the sort of concept they're referencing -- the emotional core of the experience is something that's buried under the mechanics of gameplay. Where is the resonance of Sam and Frodo's journey to Mount Doom? A similar trek in Lord of the Rings Online is a mere matter of keypresses. WoW contains many quests with a sad story at their hearts, but in the end, there is a precise path to fulfilling its goal, and once achieved, a predetermined payout. And everyone gets the same quest, so it's not even tailored to your particular emotional makeup.
So, what's missing? Actual risk. You know that no matter how badly you play, when your character dies, you return to life to try again. How much of our real lives would matter if we were free of the inevitability of death? It's the single most defining facet of our existence. We judge our actions against the day when we die, and we don't know when that will be. So if we're paying attention, our actions come to mean more. Everything we do is lent an air of greater purpose, because we choose to invest the time in doing them, time that we know is limited. Are we behaving well? Are we being kind? Are we making the right choices? These questions simply don't arise in MMOs in the same level of depth. And therefore, ultimately, our achievements can seem trivial, no matter how much time we spend on reaching them.
Finally, it must be asked: Does it matter? Do we really play MMOs with the expectation of a cathartic, life-altering experience? Statistically, it's likely that some people have had such moments, but is it the reason we play? Probably not. Perhaps all we want is engaging diversion, a way to exercise our minds in ways that real life doesn't provide. But with all the cookie-cutter games out there, all the grinding, all the sameness of gameplay, it would be refreshing to play a game that asks more of you. A game that somehow got into your gut and tweaked your insides a bit, to make you crave a satisfying, visceral resolution. Perhaps it can only come in a game where death is permanent. Maybe that's the key: the meaning of life is that it stops, and in MMOs, with their multiple alts and endless gameplay, death is irrelevant. Maybe someday someone will take the bold steps to introduce actual risk into a game. On that day, we'll start to see a change in the way this industry works. On that day, perhaps we'll start to see our avatars truly live.