I won't take your time, courtesy of NintendoWorldReport and some guy named stephentotilo (or at least he uploaded it) from kotaku we have some gameplay of some games for the 3DS
From the Kotaku guy (who speaks too much)
Kid Icarus: Uprising
Dead or Alive: Dimensions
Super Street Fighter IV
Pilotwings
Steel Diver
Ocarina of Time
Augmented Reality
From NintendoWorldReport
Footage compilation
Ocarina of Time
Kid Icarus: Uprising
Dead or Alive: Dimensions
Virtual Console
And that's it, I believe.
From the Kotaku guy (who speaks too much)
Kid Icarus: Uprising
Dead or Alive: Dimensions
Super Street Fighter IV
Pilotwings
Steel Diver
Ocarina of Time
Augmented Reality
From NintendoWorldReport
Footage compilation
Ocarina of Time
Kid Icarus: Uprising
Dead or Alive: Dimensions
Virtual Console
And that's it, I believe.