Rumor has it that the Wii U version of Tekken Tag Tournament 2 will be shown during one of the Wii U events later today. No word on what might be discussed, but one would assume they would go into more detail about the GamePad features and perhaps online play (if it's offered).
Source: GoNintendoLabels: Consoles, Fighting, Rumors, Tekken, Tekken Tag Tournament 2, Wii U