Trades that "almost" happened really aren't all that newsworthy. Because there are lots of trades that almost happen. But what makes this scenario a bit more interesting is that it sounds like Danny Ainge really was within a heartbeat of breaking up Boston's Big Three. Via Yahoo! Sports:
As the NBA trade deadline lurched into its final hour a month ago, league sources say the call Ray Allen long feared had come: Boston Celtics coach Doc Rivers was on the line, telling him he had been traded. Allen had been sent to the Memphis Grizzlies for a package including O.J. Mayo and a draft pick, and the Celtics' Big Three had come to a most brusque ending.
[...]
Before the Big Three could make it past the trade deadline, Allen-to-the-Grizzlies had to fall apart and discussions on a deal that would have sent Paul Pierce to the New Jersey Nets for an expiring Mehmet Okur contract and a lottery pick never reached completion, league sources said.
And wouldn't you know it, they turned things around. The Celtics have risen to No. 4 in the East and not just that, shown that they're to be taken seriously in the Eastern playoffs. They probably aren't a true Finals contender, but the Celtics are certainly play tough and playing well.
A deal that sent Pierce to New Jersey would've obviously been a move to open up cap space for the future along with getting a pick. Instead, the Nets pulled that same deal but with the Blazers for Gerald Wallace.
Allen is on an expiring deal and doesn't have a whole lot of time left, so Mayo and a pick would've been quality value in return for him. In all honesty, if Ainge had decided to start over and plan for the summer, those two trades would've been a good start.
Instead, he decided to give it one more run.