Looks like Bethesda served a pretty fancy 3D Vaultboy cake, as well as an equally fancy 2D cake for their press event. Here are the pics! (second one courtesy of Voodoo Extreme)
Bloody mess cake! Scrumptous, I'm sure.
EDIT: Kotaku has posted a nice assortment of pictures of the cake. And apparently:
One attending press member was so enraptured they were heard to
exclaim, "I want to taste Vault Boy in my mouth." Now that's love right
there.