The level cap is being removed tomorrow (if all goes well) and I'm here to explain how it will work. Leveling beyond level 80 will give you no additional skill points, the effects will be aesthetic only, unlocking new outfit items at level 90 and 100 when people get there. There may be additional benefits added in the future but none are planned so continued leveling is totally optional.

There will be no hard level cap from this point on, however there is an equation that we pulled from the depths of hell. The current experience to next level is calculated with the equation below.

Level Up Experience = (((level + 1) * 2) ^ 2) * 100

The new equation has the part in yellow changed to the following.

Level Up Experience = (((level + 1) * (2 + ((level - 80) * 0.6))) ^ 2) * 10

This new equation only comes in to action at level 80 (so current experience gaps remain the same). With each passing level the experience gap will become bigger at a much steeper curve than before.

You will always get the same experience you would get if you were level 80, meaning for killing someone 80 or above you'll get around 18,000 experience. The experience earned per kill will not be affected by level beyond level 80.

This equation results in the following experience gaps.
80 to 81: 2,624,400 experience (145 level 80+ kills)
81 to 82: 4,545,424 experience (252 level 80+ kills)
82 to 83: 7,054,336 experience (391 level 80+ kills)
83 to 84: 10,188,864 experience (566 level 80+ kills)
84 to 85: 13,987,600 experience (777 level 80+ kills)
89 to 90: 44,355,600 experience (2464 level 80+ kills)
94 to 95: 111,513,600 experience (6195 level 80+ kills)
99 to 100: 179,560,000 experience (9975 level 80+ kills)

In addition to these changes, hunting NPCs once you reach level 80 will only grant 75% experience. The level cap will be removed at midnight, the gauntlet has been thrown down. Level beyond level 80 if you wish but know what you're getting yourself in to.