In a thread at the Capcom-Unity forum, one user asked about Wii U backwards compatibility for crossover Wii fighter Tatsunoko vs. Capcom: Ultimate All-Stars. Hopefully you already have a copy of the game or can nab one, because Capcom's reply revealed that their deal with Tatsunoko Productions has expired, and they can no longer sell physical or digital copies of Tatsunoko vs. Capcom.
Developed by Eighting, Tatsunoko vs. Capcom was originally released exclusively for Wii in Japan in 2008 as Tatsunoko vs. Capcom: Cross Generation of Heroes before making its way to the west. The forum reply comes from Capcom Senior VP Christian Svensson, who unfortunately believes the possibility of Capcom striking a new deal with Tatsunoko is slim.
Anyone still have their copy of Tatsunoko vs. Capcom? Keep a tight grip on it!