OLC just recently announced new details of their expansion plans, with some very exciting concept art too! Basically everything
@WDW1974 said was coming is shown here.
English announcement here:
http://www.olc.co.jp/en/news/olcgroup/20150428_04e.pdf
A few initial observations...
If that is not Be Our Guest, what could be inside Beast's Castle? The castle looks much bigger than the one in MK's NFL.
Is that possibly a maze like the one at DLP for the Alice section? I see guests lining up to enter the building with the White Rabbit. Not sure if that is a separate attraction.
Lastly, this quote has me quite excited.
"The overall theme for the new themed port at Tokyo DisneySea Park will be Scandinavia with a portion of the area being themed specifically to the world of the Disney film Frozen."
It's nice to know that it will not be completely Frozen-dominated and will instead take an approach similar to Arabian Coast (where Aladdin is not the only inspiration). It looks like the Arendelle castle is possibly hosting a restaurant or M&G, while the larger mountain structure with ice castle in the background is for the huge E-ticket.
Very excited to see this develop over the next few years!