Let me start off by saying that I know this trade will not happen. It's fun though, to speculate what could happen if the right people were running these teams.
Pacers send Ellis to Kings. Kings send Gay to Nets. Nets send Thaddeus Young to Pacers.
The Kings were pursuing Ellis last summer. With Rondo leaving, Ellis could step in as a scoring point guard. This will also free up a couple million dollars more to use in free agency. Plus, they were pursuing him last summer, I would be glad to oblige and send him to them now.
The Nets get another scorer plus Gay's contract is a year shorter than Young's. They could have extra money to use in free agency in the summer of 2017 or 2018 depending on whether or not Gay opts out.
The Pacers get a starting power forward and free up minutes for a starting point guard, which they should pursue this summer.