Make sure you'll see it for yourself if you're in Tokyo :) Have no idea how long they're going to display it. Though "Xmas" writing makes me hope that it'll be on for at least a month.
upd: here's info about the illumination at Teichiku website:
http://www.teichiku.co.jp/artist/kan8/ It'll be on until Christmas, and no members are going to appear there in any kind of event.
upd2:
daytime photos from
pala4er http://pala4er.livejournal.com/4805.html