Posted by Dave Fossett on the jtrains list, Tetsudou Fan is carrying this also:
new fleet livery: http://railf.jp/news/2014/03/04/171500.html
"Toreiyu" excursion train: http://railf.jp/news/2014/03/04/173000.html
pdf on JR East's site with diagram of excursion train's modified Japanese style interior: http://www.jreast.co.jp/press/2013/20140303.pdf
All regular services trains will have the new livery by the end of 2016, and the single 6-car Toreiyu set is to be in service by the end of July.