Simply put, I don't think DZ is ever going to return to the player he's capable of being, nor make further progress towards whatever his potential ultimately is at this stage, if he stays in NY. I believe that he is capable, even currently with how poor he's played this year, of being a very, very good middle pairing player already and probably has the potential to eventually be a perennial ~45 point dman at the same time, but the likelihood of him doing so in NY is marginal now. I could even see him having a career year of 55+ in the right circumstances. So is it a good idea to trade him?
Unfortunately if we do the return will not be what you'd expect of the kind of player I just described but I think that we are ultimately better off moving him regardless because that's not the player we're going to be getting either if we hold onto him. It's a shame because it guarantees that we're going to be selling low on him. At the same time I still think he can return something that will address a need for us or benefit us more than the kind of DZ we'll be getting if we keep him. Our best bet of getting a fair return on the potential DZ actually has is probably another high potential youngster in need of a change as well. We can't hold on to a DZ who isn't going to succeed here just to avoid regretting watching him do so elsewhere.
At the same time we don't necessarily have to move him right now. If we do end up moving G, or even Stralman, without an NHL dman coming back and AV actually lets DZ play, he may be able to at least recover some of his trade value and make it easier for us to eventually make a better trade. While I don't believe he'll ever be able to return to form or reach his potential as a Ranger any more I do think letting him play consistently will help rebound his value a bit. AV's handling of DZ this far has minimalized his value to other GMs. While his play hasn't been good I think the benchings have hurt his stock more than his actual performance. Let him get in the lineup regularly; hell, even put him in a position to succeed (LD, paired with Staal or Stralman instead of one of our #7 quality dmen) and by the draft his stock will undoubtedly have risen from where it is today. Still, I think he should ultimately be moved sometime during the off season at the latest. He may be able to recover enough value to help us net a more palatable return but I don't think he can ever become that solid 3/4 dman as a NY Ranger.