TV Tokyo's up-to-date TV guide has just changed the title of the Pocket Monsters Best Wishes episode to air Thursday March 17th. Rather than the previously announced
The Rocket Gang VS the Plasma Gang! (Part One) (ロケット団VSプラズマ団!(前編)), which was still scheduled up until recently, the episode airing will be
Hiun Gym Match! Purehearted Bug Pokémon Battle!! (ヒウンジム戦! 純情ハートの虫ポケモンバトル!!), featuring Satoshi's battle with the Hiun City Gym Leader Arti. TV Tokyo has mentioned the episodes will be aired at a later date, but not given any further information on when.
Source:
http://www.tv-tokyo.co.jp/program/detail/21304_201103171900.html