Nintendo Japan has revealed 2 new Pokémon Nintendo 3DS themes: Pokémon Champion Daigo (ポケモン チャンピオン ダイゴ) and Pokémon XY Heroine (ポケモン ＸＹ ヒロイン). These themes cost 200yen each and are available for purchase as of February 17th, 2016 on the Nintendo 3DS eShop store.

Pokémon Champion Daigo (ポケモン チャンピオン ダイゴ)

Features: The lower screen features specially drawn illustrations in manga style. The upper screen features Pokémon Champion Daigo and a handful of Pokémon.
Music: ORAS - The Decisive Battle! Daigo (決戦！ダイゴ)

Pokémon XY Heroine (ポケモン ＸＹ ヒロイン)

Features: The Pokémon XY Heroine features vividly colored drawing of her and many Pokémon on the top screen. The bottom screen features various items and illustrations.
Music: XY - Miracle Trade (ミラクル交換)

Source: https://www.nintendo.co.jp/3ds/theme/list/03125/index.html and https://www.nintendo.co.jp/3ds/theme/list/03126/index.html