Well, we had one day to freak out over a DS MMO. We can all relax now. It turns out that Gungho's planned DS Ragnarok game is not going to be massively multiplayer. It's an action-RPG with some unspecified Wi-Fi use. Maybe, if we're lucky, it'll be online multiplayer on a smaller scale.
Okay, here's a thought experiment for you: what's more of a cash-in: an MMO, or a handheld spinoff of an MMO? Oh, well, we like action-RPG's better than MMO's anyway.