When Square-Enix announced Dragon Quest IX for DS, it came as quite a blow to stay-at-home console owners. If the newest rumour from EGM's Quartermann is right, DQ fans may still get a console version.
Yes, the Nintendo DS version is still coming in March of 2009, Iwada willing, but it may also be coming to the Wii. It may be coming to the little white console in the same fashion that Final Fantasy Crystal Chronicles: Echoes Of Time will — as a game playable on both platforms, with DS-calibre graphics intact. That's a money making plan that likely doesn't impact development costs like a fully fledged port would. And if we know Square-Enix, it likes to make money.
Plus, as 1UP points out, the Wi-fi enabled multiplayer would likely work just as well on both platforms.