Michael Gamble, producer of the Mass Effect series, has confirmed that Mass Effect 3 for Wii U will ship with the revamped ending.
Speaking to Siliconera, Gamble confirmed the ending won’t be a seperate download, but instead, it will augmented into the structure of the game:
“The extended ending is basically going to be part of the game instead. You won’t have to download it.”
Recent Wii U news appears to point to a November release for the console, but expect Mass Effect 3 to come much later.