Some sources for contemporary Japanese poetry:

The following are a few sites in Japanese, though much of the poetic activity in Japan still takes place off-line. (Neither Shichosha nor its journal, Gendaishitecho - major sources of Japanese poetry - have websites.)

Publishers:
Shoshi Yamada　- contemporary, experimental poetry - mostly Japanese, as well as many works in translation.
Midnight Press - journal and books
Seidosha - also publishes the journal Eureka
Azami Shobou - small press run by Fujitomi Yasuo.

Journals & Online Resources:
in/out (2003-2007)
rain tree (1997-2006)
Aozora Bunko: works in the public domain, or included with permission of author.
Shijin ga machini yattekita: archive of live readings (2003-2004)

Poets:
Hiraide Takashi 
Hirata Toshiko - (Wikipedia)
Nomura Kiwao  
Yoshimasu Gozo - a selection of poems
Kido Shuri (blog)
Yagawa Sumiko - (Hatena Diary)
Koike Masayo - (rain tree)
Yoshioka Minoru
Kitasono Katsue (Tama Art University Online Archive)

Other:
Edge (Sky Perfect TV series)