In a recent interview with Nintendo World Report, Takashi Iizuka confirmed that while the 3DS version of Lost World will have a four player online versus mode, the Wii U version will allow for local multiplayer only:
NWR: The demos on the floor are all single player. Can you discuss the co-op and versus multiplayer?
TI: We’ll have different multiplayer modes on both Wii U and 3DS. On the Wii U, there’s booth cooperative and versus multiplayer. In cooperative play, Sonic will be using the Wii U GamePad and someone can be supporting Sonic in co-op with the Wii Remote. In versus mode, one player will be playing on the TV screen and the other player will be racing using the GamePad so you don’t have to have split screen. You both have your own screen and can race each other. The Wii U multiplayer is not on the Internet. It’s basically everyone sitting on the same couch. The 3DS for the first time we’re having 4-player versus racing over Wi-Fi and the Internet.
This is nothing new for Sonic. Every one of his Dimps made portable entries have had an online racing mode since Sonic Rush Adventure, while Sonic 4 Episode 2 has so far marked the only time Sonic has had online multiplayer in a console game.
You can find Iizuka’s complete interview with Nintendo World Report here. I would highly recommend taking a look, as it has some interesting bits of info.