Ooedo Onsen...Expanded?
 

While searching for hotels in Nikko on Rakuten, I got a response about "OOEDO-ONSEN-MONOGATARI NIKKO KIRIFURI" starting in March 2008.

Unfortunately, my Japanese has degraded to the point where I can barely read at the moment (sadly, I have poor time management and a Nintendo Wii). There's an English page about the hotel on Rakuten - http://web.travel.rakuten.co.jp/port...=68664&f_ptn1=

However, I was curious if they're expanding, or if it's just a branding thing put forth by the main location in Tokyo.

Here's a link to the Japanese Rakuten page: http://travel.rakuten.co.jp/HOTEL/68664/68664.html

Here's a link on Ooedo Onsen's Japanese page - http://www.ooedoonsen.jp/shukuhaku/

Anyone know what's going on?

Hopefully you'll get better information, but my guess is that the Nikko propery used to be part of the Mielparque Chain and, as you say, the Ooedo Onsen management are expanding their brand and have taken it over.

There's more here (slightly different page)
http://www.ooedoonsen.jp/shukuhaku/nikko02.html