I stated awhile back that me and few "aquintances" (sp?) worked on an FF3j remake a few years ago... everything on the floating continent coded and all the characters, shops, maps, and systems created. but unfortunately some of the rest of my team won't allow me to release the code. they did alot of coding and sprite work, so i understand.
when it comes to what rm2k3 can do... well, if you know what you're doing (most ppl don't) you can do just about anything you can think of (with the exception of 3d stuff and few other things).
IMHO, if you want an ff2 remake... get a gba and buy DoS or god forbid Origins. as for ff3... wait on the DS release like the rest of us.