As Yoshi-P mentioned during the special talk session, there will be a tremendous amount of quests to partake in A Realm Reborn. You’ll be able to reach level 50 without completing all of the quests, but besides quests there will be other content as well, so it will be possible to level up by clearing other content too. The idea of having to level up by hunting monsters, even for your second class and beyond, will basically disappear.
Also, to touch on the new content just a bit, we will be implementing the new crystal tower and a labyrinth-like content that even players who have already reached the cap can challenge.