I'm still in the boat marked "keep all 8 defensemen". We've already seen how easy it is to have to guys on the injured list. And it's pretty common all around the league too. For the little we'd get in return for any of our lower-pairing (and higher-salaried) guys, we might just as well keep the insurance policy. (Unless for some reason we fade out of the playoff picture and no longer have anything to play for).
In the unlikely event that we ever do end up with everybody healthy (all 8 D, plus Higgins comes back leaving us with 14 forwards including Kostitsyn-who-kinda-looks-like-he-deserves-to-stay)... well... I'd still sacrifice Downey/Murray or put Kostitsyn back down rather than move one of the D. The plumbers are replaceable from within if it ever comes to that, nor would Kostitsyn be hurt by another period of suspended animation in Hamilton. Defensemen are just harder to come by.