League of Legends was patched today and it's a rather large update. It also includes the new champion Taliyah the Stoneweaver.
League of Legends patch 6.10 is live with new champion Taliyah the Stoneweaver
If you haven't patched your game yet, the downtime occurred during the wee hours, so you're good to go when you log in.
Notes on the on update 6.10 contain various balance changes to Champions. Some have has various attributes nerfed, like Alistar and Aurelion Sol for example, while Anivia and Shyvana have received some buffs.
Some item changes have also occurred. For instance, the Hunter's Machete now provides an XP reward for killing monsters at a higher level than the player have increased to +30.
Other changes were made to Summoner Spells, the map, a hotfix was applied and there are new skins available.