I've been burned too many times to say Brady is done, but....Brady as an ELITE quarterback is DONE.
He may have one last great postseason in him, but I doubt it. When it's over, it comes FAST. It doesn't usually happen incrementally. See Peyton Manning.
I hope and expect Brady to come back next season and I don't expect them to win the SB. His ego, which aided his five SB wins, will also be the thing that prevents him from admitting to himself that it's over.