First of all, this is some ideas I am going to put in my MMO, if anyone has any comments, or interesting features they are going to add in their MMO, please share them 
So i am not currently developing an MMO, but I have a Google Document that serves pretty much as a BluePrint for an MMO i want to eventually develop. I will share some specifics about it here :
The player creates their character from one of 8 races, with the obvious face, hair blah blah blah, but in addition they can choose the build of the character, with light, medium, and heavy. The character’s speed and agility both change accordingly. (the players speed and agility is also obviously weighted accordingly to their class choice.) After the player creates the race they desire with all the features they want, they are given the choice of a class to choose from. In total, there are 28 classes, with no restrictions based on race, gender, etc. The player learns several introductory spells, approximately 1 new spell or skill every level. These skills are simple, basic skills.
At level 20, the player is firstly given a quest to choose which of 3 factions to join. the quest asks the player to either participate in a pvp event or pve event to disrupt the safe boundaries between the factions. Whichever faction the player does not engage in hostile actions to, is the player’s new faction. The player also is introduced to talent trees at this level. Four separate talent trees are given to each class. Each talent tree contains new spells strictly to that specific talent tree archetype. (i.e. a wizard that specs into Fire will learn NEW FIRE SPELLS, no 10% more fire damage crap. These spells will be specifically tailored with debuffs etc. to make all of the spells work well together.)
The Player is also given a free mount at this level, and a map directing them to the faction capital city.
At level 50, the player reaches the end of their chosen talent tree for their first class choice. The player is then given an option for a second class, with no restrictions based on their prior class choice. (Balancing will be implemented to reduce OPness, such as a melee class combined with a healing class will reduce all healing spell effectiveness by 20% or something with a similar effect.) This class is no watered down version, but the whole class with full talent tree options and spells.
I have chosen to go down this route because I do not like the “tank, healer, dps” set up. To get around this, the players have this multi-class option, so they are not restricted to a specific role. Also, instanced bosses and raid bosses will not be an aggro-fest tank n spank fight. Instead, the bosses will be event-fought, and require cooperation from the whole raid, in addition to heals, dps, and the occasional aggro-grabs. In a real life situation, would an old god really just develop a grudge for one single person the entire fight? That pretty much wraps up leveling and the PvE setting.
As for PvP, there will be no instanced PvP ( besides 1v1, 2v2, and 5v5 arenas). PvP zones will be throughout the leveling experience, offering experience as would PvE. End-game PvP includes full zones solely for PvP purposes, with objectives for supplies, castles, etc.
As I stated before, this is not an MMO I am currently working on, just a very, very, very large google document of an MMO I want to develop someday.
But after my rant, does anyone have anything they would like to share? As far as features or ideas for their MMO?