It might depends on if you do all the side quest or just a few I level 53 death in stormriven hall. The side quest give like half of the main quests which is around 6000 for quests where you actually have to battle.
I believe you can easily hit level 60 before the end of Celestia. My storm wizard hasn't finished Celestia yet, and is over level 60. However, I do most of the side quests and that might be the reason why.