This is part of the rebuilding process and as someone who has accepted that sentimentality is not currently needed in these parts, I love it. Danny is not messing around -- if it takes hitting the bottom to live at the top, trading Rondo is the final step. There's no use waiting around to see how his knee pans out, how well he'll handle the rebuild, etc. Get a pick, a young talent and an expiring contract and deal him.
The Celtics can secure a top five pick in next year's unbelievable draft (I know everyone loves Wiggins, but Julius Randle anyone? Jabari Parker?) and begin plugging in future studs around Bradley, Green and Sully for the next few years. Entering 2016 I wouldn't be surprise if we're already on the rise with potentially two very valuable picks from the Nets (swap in 2017/the 2018 pick) still on our hands.