League future...
I honestly couldn't think of a way to title this. It's about Season 4, however it is more than that. It is about Riot's plans and how they are handling not just Season 4, but the game itself. This is simply my thoughts on what Riot should use Season 4 to do and how to improve the state of the game.
Season 4 should begin with Riot going and not reworking, but applying visual updates to each champion to bring them all up to snuff. This includes tuning all the skins.
Then they should put out the Magma Chamber and whatever other game mode they may be working on. This includes tampering with the team builder, introducing an improved chat system or voice chat option, giving a improve customs option, allowing custom HUD's, giving skins for the various maps as well, etc.
Then Riot should work on updating each champion's skin set so every champion has a variety of skins that provide a wide range of choices for whatever someone might like.
Then each champion should be 'balanced'. Right now each champion may be playable, but with 116 champions, obviously there may be some issues with each champion's effectiveness. Each champion has a 'gimmick' and each one should be tweaked with (strength/effectiveness wise) until each one is equally playable.
I would also like there to be events for Valentine's, St. Patrick's, Independence, Harrowing, and Snow Down. Maps and skins for each one!!! :D
Also, this is totally unrelated to the above, but I think Riot should release an app that allows for people to sign in on iOS and Android devices. Said app would allow a person to use the free champions as well as the ones they have unlocked to play a game. Not league, obviously, but something where each champion's different skills/gimmick affects the gameplay and you can earn IP on the go.
TLDR: Visual Updates Game Modes Skins Balancing Events Mobile Game :)