Wi-Fi would be lovely in theory, but Nintendo's wi-fi seems a little clunky, even on the Wii. Considering the sort of gameplay Days' multiplayer is, I'm not sure it wouldn't have its share of lag and awkwardness.
At least I still have Axie to smack around.
1: Everything about the Wii is horrible and to be hated. Everything.
2: Wi-Fi on my DS always runs just fine, even on games like FF: CC.