I think the game is as close to balanced as its ever been

No champion has over a 50% ban rate. There's usually always 1-2 with over 70%. And there are probably 10-15 champion that would be considered "meta" solo queue bans, where as you usually have a staple few that are "must-bans". That being said, I do think two champions are still a problem atm. And that's Ryze and Rammus.

Ryze: Too much damage for how tanky he gets. And imo, doesn't really have a weak phase of the game. Kind of like pre-nerf Tristana. Good in lane, solid mid-game, and unstoppable late game.

Rammus: Amazing ganks. Has a point-click Ahri-Charm. And at two items, basically becomes un-stoppable. His clears times are average, but he's a monster atm.

A few other champions I could see becoming very popular are Amumu, especially if Rammus gets nerfed. Gnar might need some small nerfs, but I think Riot should hold off from doing a lot of balancing, until the new items and map are out.