Zanon, O'Brien, and Hunwick were signed just before becoming UFAs, or in Zanon's case, as a UFA. Wilson was re-signed as an RFA. EJ was re-signed as an RFA.
Hejda and O'Byrne. Big Sexy isn't going to be re-signed by the Avalanche(at least up until Christmas, neither side had even thrown out a feeler) so I think he will definitely get traded. A Cup contender would love to have a big shot blocker/PKer on their bottom 4. Hejda, meh... he could go, but he's had the injury and was signed as an "expensive" free agent just 18 months ago.
I wouldn't move EJ and Wilson, and I'd re-sign O'Byrne if possible. The rest could go, but for various reasons, it's very unlikely that they do.