Level 50. When? Still up to debate.
It's free to lvl 15 now.
And I also find annoying that it hampers my completionist mentality. In RPG's obviously you want to do everything, all sidequests. But doing that in TOR required teaming up with groups, getting hugely overleveled so you need to skip stuff to keep challenged (or not and be bored by opponents too weak to destroy you for 10+ hours). I suppose it gets worse with the bonus quests mentioned. I only know that this was already heavily happening in the first 15 levels I played... :/