According to RPG Site, Squenix is rumoured to be working on a port of Final Fantasy IV: The After, for the Wii, no less. I guess that kind of makes sense. Sure, Final Fantasy IV Advance and Final Fantasy IV DS are GBA and DS games, but a handheld port would have more trouble being released episodically. (God knows Squenix wouldn't miss an opportunity to charge ten dollars per chapter.)
It is possible that Square Enix will simply compile the episodes into a larger game with enhanced menus, features, and gameplay for a release over WiiWare. I am not sure whether an episodic format would work well on a medium besides the mobile phone.
WiiWare might work as episodic releases can be priced low enough to make them effective and profitable.
Episodic games are released all the time outside of phones. :P Right now, there's a Home Star Runner episodic game being released on WiiWare.
But does it work well? I think that there are inherent problems with games released in volumes or episodes with an underlying, heavy continuity.
I recall that there was another series from Square Enix — maybe a Front Mission game — released on mobile phones and was later enhanced and ported to the Nintendo DS. This sounds like it would make more sense. As Square Enix continues towards globalization, however, it may appear that a release analogous to its release in Japan is more likely.