The official Pocket Monsters Diamond and Pearl (ポケットモンスター ダイヤモンド・パール) website
has posted a teaser poster stating that the series will end on September 9th, 2010
. The series will be replaced by Pocket Monsters Best Wishes! (ポケットモンスターベストウイッシュ)
. Pocket Monsters Diamond and Pearl first aired on September 28th, 2006 and will have run for almost 4 years when it ends in September. Below is the teaser poster from the official site.