The official TV Tokyo website has posted a brief synopsis for the upcoming 1 hour Pocket Monsters Diamond and Pearl 170/171 special that will be airing on April 1st, 2010. It was announced that a new variant of Dotchi ~ Nyo? (ドッチ~ニョ?新バージョン登場!) will air during that broadcast. No further information regarding the variant was announced.
Source:
http://www.tv-tokyo.co.jp/program/detail/19406_201004011900.html