Tekken Tag Tournament 2: Touchscreen controls. Specifically, the WiiPad's screen can be used to map out custom shortcuts to specific abilities, which can then be tapped in succession to perform combos.
Series producer Katsuhiro Harada demonstrated the feature during a pre-Tokyo Game Show event at Namco Bandai's headquarters in Shinagawa, Tokyo, wherein banks of on-screen buttons were pressed to activate moves that would normally require directional inputs and/or simultaneous button presses.
If this sounds at all familiar, its because a similar system was implemented in Dead or Alive Dimensions on the 3DS, though from everything we saw it did not appear as though TTT2's shortcuts can be used to perform entire combos with one button press, as is possible in DOAD.
We asked Harada if WiiPad shortcuts will be available for use while fighting online, and he said that he wants that to be the case. He made it a point to mention, however, that some moves (such as the Electric Wind Godfist) will not be executable as shortcuts, and that a classically-skilled player will still have the advantage.