I think I would consider a deal like the one you mentioned:
Atlanta gets: Dwight Howard, Hedo Turkoglu
Orlando gets: Al Horford, Joe Johnson
Simply based on the fact that it rids us of Joe Johnson and is horrible contract.
I hate that we would lose Horford, but it sets us on the rebuilding path, which could very well be what we need barring a miracle.
I really doubt Orlando would want to take on Joe though because they have already used their amnesty on Gilbert Arenas.