Until then, the GamePad is no use for Virtual Console titles.
The Wii U will be receiving its own Virtual Console service in the future, Nintendo's Satoru Iwata confirmed. Until its arrival, however, players cannot expect to be playing Wii and Wii Virtual Console titles on the Wii U GamePad.
As confirmed by our Japan correspondents, a post on NeoGAF's gaming forums quoted Iwata to say "We understand that there are people who were looking to playing Wii games, Virtual Console games, and so forth on the GamePad, but unfortunately we cannot accommodate those users' expectations."
As it stands, Wii Virtual Console titles are only available to play on the Wii U by putting the system into Wii Mode. From there, only accepted Wii controllers are allowed for use.