The update for Toki Tori 2 is now available for North American Wii U owners as well. To recap, the update does the following:

Improved the flow of the game after reaching the room with the 'thing'
Added another super-secret area
Fixed a bug where Toki Tori was invisible after returning to the game
Fades between levels now fade the audio too
Simplified the puzzle in the underwater passage
Fixed an issue when the TokiDex was completed in the photo room
Some back- and foreground elements got a fresh coat of paint
When all the collectibles in a level (or the entire game) are collected a melody will play to notify the player
Fixed a rare bug where the player completed the game, but the end scene wouldn't trigger
Various level tweaks, based on Miiverse feedback