You've let your imagination run amok again Ottawa. Depth has not been one of the Senators' strong points for the past couple of season, but moderately talented, inexperienced players do not take the place of experienced NHL regulars. (I think I said as much in the last post.)
So while you're drooling that Matt Carkner (why did I not hear of this amazing talent before this season?!) may take the place of Chris "heart and soul" Kelly and his $2.1 million contract, try to remember why he was offered that contract. Kelly is an excellent penalty killer, an occasional scorer, and a solid defensive forward.
I'm not sure exactly what kind of return you're expecting to get for the likes of Christoph Schubert and Chris Kelly, but it's a fact that 4th round picks can't kill penalties or score goals. Hell, even Carkner probably won't.
So before you go throwing the baby out with the bathwater, try to remember that baby is pretty good at hockey. And your bathwater is inexperienced at penalty killing at an NHL level.