Oh, ok. Ys Celceta is basically Ys 4. It's Falcom's version, since Dawn of Ys is not cannon, & both Masks of the Sun...kinda suck. There was an X68000 Ys 4 planned as(not to mention an MD version as well). The X68000 game robably Falcom's own project, not sure why it was cancelled though. I have most(or all) of the soundtrack(ripped it off youtube), & interestingly, there was a version of Arem's theme in teh X68 Ys 4, even though Arem seems to only appear in Dawn.
Hopefully Ys Celceta will take more after DoY, as even Nintendo fanboys tend to choose that one over either of the MotS's.
As for the Ys 7 multi-plat. It's been awhile, so my memory is fuzzy, but there was some sort of documentation someone tracked down indicating it being on more then one system. There is currently a Chinese PC version in the works, but, I personally think(& hope) there's maybe a PS3 version in the future. I get most the info over at the Ancient Land of Ys boards, so it might be best to ask over there.