It's called, "try hitting on anyone while you're wearing that thing." That's right, Harry Potter there is someone's husband. So if this sweater makes him the world's biggest geek, it also makes her the world's most awesome wife.
Reasoning that "knitting stitches are basically pixels, right?" The Happy Seamstress converted World 1-1 into a "ginormous knitting chart made up of over 10 sheets of tabloid paper taped together." From that she made the sweater, which has to be the Conversation Piece of the Apocalypse.
She even specially dyed yarn to make the pipe and bush the appropriate colour. The pattern is not yet posted; she promises that's on the way soon. Meantime, she's published her list of supplies. I foresee a run on "KnitPicks Palette in Pool" at your local Michael's. The Nerdiest Sweater Vest in the World [Happy Seamstress via CrunchGear, thanks Chris]