The PBE has been updated and tons of new information is pouring in! The patch included new skins, the Ashe graphic rework, and the graphical changes to Summoner's Rift.

Thanks to Slushe, I present you the newest skins to hit the Fields of Justice. We have a new Amumu, Shyvanna, and ( FINALLY ) Swain skin! We also have some shots of the new Ashe models ( reposted from redditor Dyloslawer ).

Sad Robot Amumu


Darkflame Shyvanna


Tyrant Swain


Ashe
( Model Remake )

Default


Woad


Freljord


Queen

Amethyst Ashe also got some new spell effects, but I'm not exactly sure if these animations ( obviously sans recolor ) are exclusive to her or are also present on the other skins as well.

Check out this rather lengthy video, courtesy of State Of The League, highlighting the excellent Summoner's Rift graphical update.

Some ****py screen caps of the new monsters! They come complete with new animations and models.
Image Courtesy of Redditor das_Es, showing off the new ground coloring.