Doing trades for the sake of doing trades is what turned the knicks into a joke of a franchise. Doing trades for the sake of doing trades is what made Isiah universally known as the joke he is.
This teams lives and dies with KG's knees. If he never gets back to about 70% of what he was, we won't contend for a title, regardless of who we could have gotten for Ray. If KG is done, this team is done, and players like Kevin Martin, Monta Ellis and all the other rumors would just be so the team was good enough to win 40 games for a decade.
If KG is done, it is best to win 50 games this season, 40 the next, then let the contracts expire and try to make a splash in the 2012 free agency (potential free agents: Durant, Rose, Dwight Howard, and so on).