The USB wireless hotspot adapter things are going to be everywhere when DS gets online. There'll probably be PSP ones as well so it's not just going through tunneling.
As for Animal Crossing, it's fun but got repetitive because it was a 'fake' social game. Once it's online, it'll be far better, especially since you'll be able to actually get a job and such (hopefully not just at Tom Nook's - imagine being a policeman and stuff as well!), and there'll be more customisation in terms of your house, etc.
Still, I've not reached the point of the topic - my prediction for Animal Crossing DS is, soon after E3, perhaps even as early as late June so that they're competing with PSP's online functions. It wouldn't surprise me if they're translating as they go along either so they can pass it over to America and Europe pretty sharpish.