One of the big selling points of the Virtual Console service was support for Nintendo and non-Nintendo platforms. SEGA saw how successful the VC service was on the original Wii, so why are they withholding support now? They put stuff on the 3DS VC and 3D Classics, so why not port the existing VC games to Wii U?
At least we have Capcom's support. Now all we need are Konami, Namco, Square Enix, etc. All these companies put games on the Wii VC, so they can easily port them to the Wii U because the two systems share very similar architecture.