This is who I'd have on the trading block because I think they are hurting the team and I don't believe they are ever going to turn things around (because of age, injury, motivation / attitude, etc):
Oshie
Eller
Mantha
Kuzy
This is who I'd have on the trading block because they are UFA's etc and unlikely to be re-signed, so might as well get something from them:
Gus
Sheary
Aube-Kubel (likely has next to no value but Protas or Snively should be playing ahead of him anyway).
Irwin (see above)
Guys like Hathaway, Majo, TvR - I believe they are earning their salary and could return next season and still be useful players on the roster (so they go under the let's not blow it all up category).
Orlov - if he's not going to re-sign then he should be moved or he will depart for no return end of season.
Jensen - will be looking for a decent raise and term for his final contract so is similar to Orlov (see above).
Backstrom - he's not going anywhere. People need to just stop talking about him and face reality.