I don't think anything is officially planned as of now, but it seems logical that Square will potentially get around to re-releasing every classic FF on the DS. FFIII last year, FFIV this year... Maybe FFV in 2008? I'm personally frothing at the mouth for a DS incarnation of FFVI.
OMG NEED PS3 REMAKE OF FFVI. I kid, though I wouldn't be opposed to it :D. I am a little worried with a remake of FFVI with any other graphics than that of the SNES, since the recent trend in SE sprite design irks me (happy/kiddy and obviously so).