Reading Poolswimmer.
The most interesting thing I've seen Japanese do differently in this game is using Rumia for Plus Disk. Other than that, they pretty much use the same characters.
OH GOD YES, sounds like they may have buffed Rumia. Hopefully. Before this, she's only been an utter waste of art and programming effort; all the other characters are at least usable, even if unrecommended.
http://www.nicovideo.jp/watch/sm11200309
If that video is real then you can choose how many levels you want to level a character... much faster than clicking z all day...
Awesome. Plus Disk made it less bad by giving memory on which stat you boosted on levelup, but this makes it so mass leveling isn't a big deal at all.
EDIT:This might be the only thing they meant when it said "reduced grinding", by the way. :x
Also, here's a video of fighting 12F boss in Special Disk.
http://www.nicovideo.jp/watch/sm11186700 FYI, the omgraep nukes didn't even get used, so if you knew about that whole "oh man they nerfed the difficulty a ton 12F nukes hardly hurt you " discussion, yeahno. I don't even know how that happened, unless someone mistook a regular attack for a supernuke.
Here's one of fighting 30F last boss.
http://www.nicovideo.jp/watch/sm11163685This shows the ability to switch your character our-...I just got some weird japanese virusthingy that tried to shut down my computer and played some words I can't understand. It closed everything except firefox because it asked me if I really wanted to close multiple tabs at once XD Well, keeping one thing from closing cancels shutdown, for you people who don't understand why I'm still typing. Anyway. Shows the ability to switch out your character artwork for other stuff, and two new songs. The other two videos also show one new song, each.
And YES, that is RUMIA you see him using for 30F boss. It really is. Demarcation seems to be healing a about 1.33x as much as Meiling's Healer (and a little less then half as much as Reimu's), and Moonlight Ray doing about 4/5th the damage of Youmu's Slash of Eternity. Well, her MAG apparently might be better. If her survival ability and/or speed have improved, she may be okay now.