Aren't there two lines of Just Dance games, the regular one and the "4 Kids" version? That could be two of the eight, though I have no idea how reliable of a source this guy is (never heard of him before).
That casual "Know Your Friends" game for Wii U that Ubi Soft finished but never released could also be one of the games.
I'd be down for some portable Assassin's Creed or South Park though.