Yahoo Japan has announced the 2008 Search Word Ranking from January 1st, 2008 to October 31st, 2008. Pokemon's popularity doesn't seem to be declining in Japan as it placed high in most the search term categories. Below is a list of categories with the rank that the Pokemon related searches placed.

Rank	Search Keyword	Search Category
1st	Shoko Nakagawa (Shoko-tan) / 中川翔子 （しょこたん）	Female Celebrities / 著名人ランキング女性編
2nd	Shoko Nakagawa (Shoko-tan) / 中川翔子 （しょこたん）	Overall Ranking of Celebrities / 著名人ランキング総合
1st	Pocket Monsters / ポケットモンスター	Anime Game Rankings / アニメ・ゲームランキング

Source: http://searchranking.yahoo.co.jp/ranking2008/general.html