Tom Crago of Straight Right has confirmed that “Miiverse functionality isn’t in [the Wii U version of] Mass Effect 3″, explaining that:
In the context of the game we never really talked about it. However, it’s something we’re interested in as a studio and with future titles that we might release we would love to look more into it.
This doesn’t feel like a big surprise though. I doubt most of the ports will contain the less instantly-obvious features of the Wii U. For the most part, the tweaks are going to focus on the GamePad, since that’s what people see first.