I really haven't talked about it with them yet. I think it's a combination of them being (relatively) young, and the fact that we don't have TV/Cable/Satellite. I don't know if Pete would ask about it, and Teddy hasn't really seen much to ask about. So I'm not bringing it up unless one of them does see and ask.
I've got thoughts in my mind regarding what I'd say if he does see something and ask about it. I suspect I'd tell him that Osama bin Laden was a very bad man who hurt or killed a lot of people. He didn't like America very much and that's why he wanted to hurt us. Someone killed him because he wanted to keep killing people and they thought it was the only way to stop it. Yes, killing is wrong. And that's why Mommy is both happy and sad because of Osama's death.
And no, Osama was not our president. That is Obama and he isn't a very bad man who hurt or killed a lot of people. (Yeah, I'm already mentally spiraling toward the off topic questions that I'm sure he's going to have.)