The game is more balanced than it has been yeah, but it's far from being properly balanced. I'm a game designer and from my perspective here are some things that need to be tweaked.
Some Mages (to an extent) and Warriors need to be toned down. Warriors are too damn strong at this point mostly due to a lot of the early game items being nerfed for assassins with the rehaul a couple months back. Honestly if it was up to me that role wouldn't exist. My philosophy is you either deal a lot of damage with limited tankyness (both kit and items) or you don't while maintaining great disruptives with team utility A.K.A Assassin or Guardian. You can't have both amazing tank and strong damage stats on one role it doesn't work in any moba. On top of that they are hard as shit to properly balance because they will either be overwhelmingly strong or useless.
The bruiser class in league is a similar role and it has become a big issue to the point that Riot has to rehaul the whole class. I really hope hirez doesn't let it get out of hand like LoL did or it's going to bite them in the butt down the road.
Some items need to tweaked. Mostly gold value issues here, but nothing big since the revamp.
Some actives need to be nerfed into oblivion *cough*beads*cough*. - I'm fine with the whole concept, but a 300 gold item should not completely counter most CC based ultimates. A good start here would be to remove the stupid CC immunity at the very least early levels of the item.
I would go into God kits, but that would make this post way too big. LOL
Some Mages (to an extent) and Warriors need to be toned down. Warriors are too damn strong at this point mostly due to a lot of the early game items being nerfed for assassins with the rehaul a couple months back. Honestly if it was up to me that role wouldn't exist. My philosophy is you either deal a lot of damage with limited tankyness (both kit and items) or you don't while maintaining great disruptives with team utility A.K.A Assassin or Guardian. You can't have both amazing tank and strong damage stats on one role it doesn't work in any moba. On top of that they are hard as shit to properly balance because they will either be overwhelmingly strong or useless.
The bruiser class in league is a similar role and it has become a big issue to the point that Riot has to rehaul the whole class. I really hope hirez doesn't let it get out of hand like LoL did or it's going to bite them in the butt down the road.
Some items need to tweaked. Mostly gold value issues here, but nothing big since the revamp.

Some actives need to be nerfed into oblivion *cough*beads*cough*. - I'm fine with the whole concept, but a 300 gold item should not completely counter most CC based ultimates. A good start here would be to remove the stupid CC immunity at the very least early levels of the item.
I would go into God kits, but that would make this post way too big. LOL