Could Nucky be Jimmy's biological father?

I feel like it's heavily hinted at throughout season 1. Firstly, it's strongly implied that Nucky had a romantic relationship with Gillian (Jimmy's mom). Second, there's that strange monologue that Jimmy has with that whore from Chicago where he's telling her about a perfect day where he went sailing with his mom and a gentleman caller. In addition, there's an exchange Jimmy has with Nucky in the season finale when Jimmy is hammered and Nucky looks at him with a stern look in the eyes and says: "I am not your father James." Lastly, I feel like it would best explain exactly why Nucky felt such responsibility for Jimmy as a guardian throughout his life. The mere fact that he was the one that introduced the Commodore to Gillian doesn't cut it for me. I think there NEEDS to be more.

Whether it is left purposefully ambiguous or not or it's something that will be developed in Season 3 is a mystery to me, but I really do think there's something to this.