What Nintendo needs to do is leverage the Castlevania DS demand to get it.
Knowing Sony will reject a 2D title for the PSP very quickly, Konami would be in a bit of a quandry if Nintendo said "DDR on Cube, or Belmont goes homeless!"
DDRMax US on the PS2 is only 1100MB. It'd play just fine. We don't need special features. Just. . . yeah. The core game!