I would say rested bonus, but instead I thought about it and concluded that rested bonus doesnt count towards quest/leve reward exp, at least in 1.0. Nothing about a change to that was said for 2.0. And while monster grinding will not be the main way to go in ARR as it was with 1.0, I have to conclude that they either extend rested bonus to quest/leve exp, or have a double EXP weekend.