Well, they're usually kind of stingy with it when it comes to Superman and Batman (pre-Morrison). To my knowledge, there's never been another Superman operating while Kal is around outside of alternate reality versions of himself which I exclude. Plus, I assumed, like a lot of people, that they really wanted to give Jon as much room as possible to stand out.
Crazy part is Bendis was the guy that requested for Young Justice (and by proxy Conner) to come back even while he's writing Jon. That speaks to his confidence in the story line that he has cooking for Jon, in my opinion.
Also good point on mentioning that he brought back the original Guardian. I almost forgot about that. I'm operating under the assumption that Bendis will be giving Conner some approximation of his early history, but leaving out the shared history with Tim, Bart, and Cassie since Tim has no idea who he is. So I'm expecting history with Guardian and Cadmus.