@Kren considering the nature of RPG
No we assume that the leveling progress is part of the genre. But it really isn't the earliest MMORPG's used a long level grind as a way of milking money from their fan base. While I'm not big into DnD, you use levels to mark increases in skills, which states progress along character path. This translate well via an xp system to online gaming, given large distances between levels you can create long grinds.
Really end game content was the biggest addition to the RPG genre by giving people something to do once they have reached a 'level cap'. I believe Evercrack (inb4 darksend yells at me for being wrong) was the first MMO to really allow 'level capping' and having end game progress' which allowed players to level post max level.
This 'post level' system could just be easily used in place of leveling system. Get items to be more power to get better items. Use quests for gating progress make BoE's rare to allow for better progressed characters to make money but still allow experienced players to rush the progress and looky there you just created a 'leveling' system that actually makes your character do things, and learn to play in a PvE environment.
[Today 06:48 PM] Ion:swimming in a natural body of water ISN'T acceptable...it's momentarily tolerable