Development on a Virtual Console of downloadable titles from older systems is currently underway for the Wii U, Nintendo confirmed with Polygon today.
"We do not have any specifics to share at this time," a representative for Nintendo said when asked when we can expect the Wii U version and what platforms the library will cover. "However, we are moving ahead with development of a Virtual Console for Wii U, too, and we plan to make it so you can play it on the Wii U GamePad alone."
Currently both the Wii and Nintendo 3DS have their own Virtual Console libraries. Titles from the Wii's Virtual Console are accessible on the Wii U through a file transfer process, and can only be played using classic Wii Remotes.
The Wii Virtual Console was available day-one alongside the console at launch in North America on November 19, 2006. The service launched on the Nintendo 3DS eShop in June 2011, three months after the handheld's release in March.