There was a great opportunity here for Nintendo to set up their own Nintendo Wi-Fi Connection servers, change the code of games like Star Successor so they point to the new servers, and distribute the new version via the Wii U eShop. Maybe that'd be too much work, but fans already make unofficial modifications to do the same thing, and Nintendo already seems to change these games so they support the Gamepad. I guess it could be a rights thing with Gamespy or something.
Or you know, thinking about it, why didn't they release a general update to the Wii Disc Channel via the Wii Shop Channel? It would check the game you're running, and if it's a game with Wi-Fi, it would on-the-fly patch in new server info. This is almost exactly what homebrew apps like Riivolution do. Huh. Still too much work for old games, I guess. But man, it totally seems possible!