I guess that would make it only a kernel update. The firmware update allowing SDHC support should come out sooner or later. Or that posted DAT file could be a kernel 1.11 file that is modified to say "1.12" on the title screen.The English version of 1.12 had been released to limited members in JAPAN.
http://2sen.dip.jp:81/cgi-bin/upgun/up1/source/up9213.zip
All this is is a _DS_MENU.DAT file
EDIT: The system does this when booted -- i didn't press any buttons b/c not sure what the hell this is:
EDIT: Okay, better not add that into your memory card. I don't like the looks of this, could be a bricker
It seems to be a homebrew breast simulator (oppai = japanese for tits). So, yeah, not a bricker, but not the new firmware either.