Riot has just released a new League of Legends trailer, introducing the preseason 2014 changes. And believe me, there are quite a few of them. Upcoming tweaks will alter in-game roles (most notably supports), the introduction of trinkets, neutral monster levels, and so forth.
Additionally, towers will give greater rewards to the player who destroys them, but won't affect other lanes as drastically. Similarly, destroying inhibs will only impact one lane, which means the team that loses said their inhib won't be forced to turtle and defend quite as much.
Supports and junglers should be happy with most of these changes. Have a look-see.
Thanks for the tip, Invidia!