It's happened before. Recall Bledsoe trade? You could look at it as their season is over and taking draft picks from your divisional opponent to strengthen yourself long term. I just hope the GMs are conversing on the subject.
I've said it before and I'll say it again, Brandon Marshall. He still has a little something left, and can make contested catches. His contract extends through 2017 so it isn't a one and done deal.