If the Magic aren't sick of Danny yet I think this deal should happen:
Rondo for Ryan Anderson and Jameer Nelson. You get a guy who is young and can rebound and a slightly above average point guard who is modestly underperforming at 9 ppg and 5 apg and a 2.5 to 1 assist to turnover ratio.
Why the Celtics Do it? They get a 23 year 6'10 big who can rebound and shoot with range who can contribute right away and help extend KGs career another year or two. They also receive a steady on offense point guard who can body up to bigger PG's and demonstate the veteran leadership necessary to be consistent in a playoff push with the big three. Nelson can be the bridge and mentor to a successor point guard in 2012.
Why the Magic Do it? Securing Rondo is one of the best way's Orlando can entice D-12 to re-sign. Rajon will get Dwight the ball and give them a realistic chance of keeping him in Central Florida. Orlando also gets a younger point guard with superior defensive skills.
I checked the trade machine. The salaries work and the win differential is 0 for the C's and -1 for the Magic.
I think this makes us better now by addressing two major weaknesses: consistent PG scoring and interior rebounding.