Obviously, the Braves thought it was a good time to sell high on the best defensive shortstop in the game. While lefty Sean Newcomb has potential to be a top-line starting pitcher and Chris Ellis could be a decent rotation piece, this seems like an underwhelming return. The Braves do get Erick Aybar coming off a down year and going into a contract year, so they get an obvious replacement for at least 2016.
The primary motivation for the Braves here seems to be saving money. Simmons is due $53 million over the next five years, which if his defensive value continues to remain so extraordinary, isn't all that bad. The issue is more with his offense, and if his bat will start to take too much away from his overall value to keep him an above-average regular. The Braves figure that they'll move on and get a couple of arms to add to the stockpile. While I feel like this is a move that could come back to haunt the Braves, it's obvious that the Angels really, really love Simmons' glove and with their own shortstop a free agent after 2016, you're not going to find a better option on the free agent market.