It's a combination of a few different rumors
LAL gets Josh Smith and Rondo
Atl gets Pau and Metta
Boston gets Devin Harris and Devin Ebanks
Atl does this to get Pau back in time for the play offs and give them a nice upsurge in energy and experience for a play off push and would potentially allow them to have the best front court in the East with Horford and Pau inside. Korver playing the three to stretch the floor. Plus gives them a solid defender in Metta to go against the likes of Melo and LBJ in play off series. In the short term, MWP can man the 4 until Pau gets back.
Boston needs a PG after Barbosa and Rondo's injuries. They get Harris, and make a run this year. He can distribute the ball on a veteran gritty team. If it fails, he can walk at the end of the season and Boston can start shopping PP and KG for the rebuild process. They lose nothing for this season, get a young wing and a PG to give it another shot and if they do OK can resign Harris in the off-season. Plus, I'm not sure when the tax penalty is calculated, but if it's at the end of the season, Boston would shave enough off their salary to go from a payer in the revenue sharing system to a recipient.
LAL gets the PG of the future and gets what Jim Buss wants with a new version of Showtime starting next season. Rondo at Point, Kobe, Earl Clark, Josh Smith and Dwight starting. Nash, Meeks, and Hill providing energy and experience for the second unit with a couple of FA pick-ups.