The official Diamond and Pearl anime website has announced that there will be a new opening theme song and a new ending theme song which will begin airing on October 2nd during the Ginga-dan special. The opening song will replace 'Together' which has been the opening theme since the series began in 2006 and will have aired for over 2 years when the new opening replaces it. Below is some information on the new songs.

Opening Theme
「ハイタッチ！」 (High Five!)
サトシとヒカリによるパワフル＆元気なポケモン初のデュエットソング！(Satoshi and Hikari sing their first cheerful and powerful Pokemon duet!)
作詞：戸田昭吾 (Lyrics: Shiyougo Toda)
作曲＆編曲：たなか　ひろかず (Composer and arranger: Hirokazu Tanaka)
うた：サトシ（松本梨香）＆ヒカリ（豊口めぐみ）(Sung by: Satoshi (Rica Matsumoto) & Hikari (Megumi Toyoguchi)

Ending Theme
「あしたはきっと」 (ashita wa kitto / Surely Tomorrow)
ピカチュウやポッチャマたちの姿が目に浮かぶようなカワイイ仲直りソング！(A cute song with appearances by Pikachu and Pochama)
作詞：須藤まゆみ (Lyrics: Mayumi Sudou)
作曲＆編曲：三留一純 (Composer and arranger: Kazumi Mitome)
うた：歌奈子 (Sung by: Kanako)

I\'m looking forward to these songs. It\'s kinda nice that we get both a new opening and a new ending at the same time. Hopefully the songs are good.

Ahh, if only GARDEN could\'ve sneaked into there somehow!

That's pretty cool that they'll be singing a duet. It's interesting that they actually say it's the characters singing instead of just their voice actors. Even though Rica Matsumoto has sung a bunch of opening/ending themes, they weren't necessarily "in-character".

I never did understand why Megumi Toyoguchi wasn't the singer for "Kimi no Soba de", but hey, it'll be nice to hear her sing this time.

I hope the animation sequences for the themes are good too.

At last!!!! Seriously, Together was starting to piss me off!! It is a good song, but after hearing it for two years long, it starts to get boring. Well, I'm looking forward to both of these songs to see if they'll be good. I hope so!

P.S. I can't wait to see if there will be a new Battle Frontier saga! Hopefully it'll have good OP/ED too.

Wait is this America?

Dialga - No, this is referring to the Japanese anime. However the dub will most likely have a new opening for whatever comes after Battle Dimension. It will probably be totally different to these because of the much shorter length of the dub openings.

NO MOAR TOGETHER! ME HAPPY!

I hope these songs will be high paced, like \'Battle Frontier\', they often turn out great as instert songs in the anime. I don\'t want a slow paced opening a\'la Symphonic Medley.