Actually, I was reading a post on the GFAQs boards, and someone posted how it could actually be possible to port FF7 to the DS. The game is on 4 CDs, which is like 20 DS carts or something like that, but most of it is FMVs. If they cut or compressed the FMVs, and compressed the whole game, with the technology today, they could fit it on a DS cart, and the gameplay portion would probably look better than the Playstation.
Doubt it'd happen though, although Square seems to be really getting along well with Nintendo lately. o_o;
*is still hoping for KH to move to Wii* XD