You can level as many characters as you want, as everything is reset if you create a new character.

If you meant levelling other classes then no, you only have enough quests to get to 50 on one class. But with the addition of dailies for level 42+ and all the bonus experience to be had in the Roulette, it's not that bad at all. Add to those things each class's hunting log, a couple of FATEs here and there when you chance upon them, and the dungeons and you can reach 50 without too much hassle. It definitely beats the FATE grinding from before.