H!P will participate with 46 performers.
Main acts:
Morning Musume: 9
Berryz Koubou: 7
℃-ute: 7
And 23 eggs:
新井、前田彩、小川、関根、岡井妹、佐保、福田、前田憂、和田、古峰、北原
森、西念、古川、吉川、武藤、澤田、仙石、田中杏、真野、青木、能登、是永
(source: anonymous 2ch-er)
Takahashi Ai comment in the news: 「今年は中国からのメンバーが参加したり、中国、台湾、韓国に進出できて成長できた1年だった。モーニング娘。の10周年記念の年の幕締めとして、楽しみたいです」
「This year was one year that was able to participate by the member from China, and was able to advance to China, Taiwan, and South Korea and to grow up. I want to enjoy it as tightening the act of morning daughter's age on the tenth anniversary.」
http://www.sponichi.co.jp/entertainment/flash/KFullFlash20071229004.html
On the 29th the rehearsals started.
Some low quality images:
Berryz Koubou