The artist's CV noted that he's been "providing animation and R&D for a new AI companion character" in Infinite. [Editor's note: This has since been removed.] Who could it be? Songbird? One of the Luteces? A dog? BioShock seems like it could use a dog.
Elizabeth seems like she'll be a tough act to follow, as Tom Bramwell made clear in his glowing review, but if BioShock Infinite taught us anything, it's that Irrational is full of surprises. We've reached out to Irrational for comment and will update if we hear anything back.