According to G.Rev's latest magazine entry (here, or you can see the babelfish translation here), the regular edition of Under Defeat has completely sold out and they've had to do a reprint. Apparently, there's not many of the limited edition left either. This appears to have come as a bit of a shock to them!
Wow, we knew that Under Defeat did well,(was No1 in sega's "Sega Direct" shop in their charts, when released). But SOLD OUT.... Thats cazy!
Things are look good for the Dreamcast (well in japan at least)