Izzy will be a loss for sure, but it makes me believe now that Paea and McClellin are in seasons where they must perform. No one will be complaining about losing Idonije if McClellin has 7 sacks and Paea is better up the middle.
As for Moore, I find it hard to believe that's a big loss for the Bears. I believe they'll take a CB with one of their first 3 picks, even though that guy is probably not a future nickel. He'll compete with Hayden for the nickel spot in 2013. If he wins, he plays. If not, he plays if Hayden, Jennings or Tillman get hurt. If he shows promise, they might think about releasing Tillman after next year?