According to a comparison on Technorati there are more blog posts on Kanji than there are on Hanzi:
Just speculating: The interest in Japanese, and thus Kanji, has been very much an off-spring from the Manga/Anime culture, mostly populated by young people. Those blogging are usually more on the young side, still these days. Young + young = more Kanji than Hanzi. This will most likely change dramatically over the next years when more and more people either migrate from Japanese to Mandarin/Chinese and newbies pick Mandarin instead of Japanese.