Super Street Fighter II: The New Challengers is coming to Wii's Virtual Console, Capcom has announced. "But... didn't that happen in 2008?" you may ask. Ah, you poor, dear, sweet fool, that was the SNES edition--this will be the Genesis version, with online multiplayer.
Online multiplayer was absent from the Virtual Console release of the SNES version, but will indeed by in the Genesis VC edition, Capcom says.
As for other differences between the two versions, the unofficial Street Fighter wiki says that the Genesis edition has an exclusive option to select the number of characters faced in Super Battle Mode. However, it is supposed to have lower-quality sound, so it's all swings and roundabouts.
It'll hit North America and Europe as well as Japan, but western release dates haven't been set yet.