Yeah, In the Groove for PS2 looks like it might end up being something of a rarity. It just came out, and it's already a little tough to find. I don't have any specific numbers on production runs, but the EB I picked it up at had exactly 2 more copies besides the handful of preorders. Might want to keep an eye on this one...

And it's just a hell of a fun game, if you like DDR and Euro club music. Heh.