No Online Multiplayer for Pikmin 3.
In a recent interview with the series creator of Pikmin, Miyamoto stated that the upcoming Wii U title, Pikmin 3, will not have online multiplayer. Miyamoto said:
So in the case of Mario Kart, we did have online multiplayer, and that's something that... You have to be very careful that you don't drop frames as you're trying to sync up with other players over what could be a very great physical distance, over the internet. But in the situation of Pikmin, for example, since you would have lots of individual, small creatures, the Pikmin, whose every movement and location is going to be really important in the game, it would be very difficult to sync up over an internet connection.
So I think what we've decided to do is focus on the single-player and local multiplayer aspects, which are really fun. But unfortunately, no online multiplayer for Pikmin 3. But the co-op local multiplayer is really fun.
Pikmin 3 will be a launch title for the Wii U and will include local multiplayer, but no online multiplayer.
Source: Nintendo Life