The more I think about it, the more I think Rondo is a goner... I think Ainge knows what Rondo is, an above average point guard who is regarded as a Top PG because of his situation. I think he is going to be heavily shopped this off season.
When the Big 3, or part of the Big 3 is gone, Rondo is going to become devalued quickly. He would be tougher to trade and you might not want to live with him, his attitude, and his up and down play for the future. Rondo won't be the same guy without those guys to inflate his assist totals and open up the floor for him.
I think Rondo is OVERvalued at this point and Ainge has a real shot to cash in on that and extend the life of this team's viability.
I can really see a Rondo for Conley/Marc Gasol type deal where a small market team wants a star PG and doesn't want to pay a guy who is up for a contract... I am just throwing that out there, but I could also seeing them trying to package him with picks and another player to try to land CP3 or Deron.
I like Rondo, but Ainge is a business man... I think he sees Rondo as his one monster chip, and I think he looks to cash it in.