Trading Rundblad for anything less than what he is would be counterproductive. Trading someone who could potentially be a first pairing defenseman for the rest of his career for a someone who's remaining career length is probably a year...that would be giving up.
If Rundblad doesn't turn out to what we think he could be, then whatever, we took a gamble that 29 other GM's would've taken, while also ridding our organization of a whiney twerp in Turris. With that said, I think we can all agree that it is looking like he has a greater chance at reaching his potential, than not. If you are one of the few that has written him off completely, you belong with the other 12 year old kids on the main forum who say Ovechkin's career is over, and that anyone drafted 2010 or earlier that hasn't played a game in the NHL is a bust.
The safer hand to play in this situation would be to keep him and give him a genuine shot. If you were going to trade him, the time do it has passed. His value is probably at an all time low, due to the fact that people are starting to doubt that he can crack an NHL roster because of the depth we possess. Then, a defense desperate team calls you and offers you a player that is older and past his prime, but makes you believe you are coming out on top due to the fact that you are receiving tired, but proven production while they take the risk for you. That's when you make the mistake that Montreal did, and trade McDonough for Scott Gomez.