I think Smith + Rondo would work beautifully together offensively - very similar to the Nash/Marion duo that was so potent in Phoenix. The Smith/KG frontcourt pairing is also extremely appealing.
Very difficult to construct a deal that would be pleasing to Atlanta though. If Jeff Green can play his way into positive trade value, maybe.
I think there is a HUGE difference offensively with Nash/Marion from Rondo/Smith, because of the dramatically different shooting abilities. But, defensively, Rondo and Smith would be a scary combination.
I agree that there just aren't many deals that make much sense for both teams though.
Not that huge. Rondo compares pretty favorably to Nash as a transition creator (the most powerful aspect of the Nash/Marion tandem). Smith, like Marion, needs a great transition PG to become a highly efficient scorer (Marion, though a better distance shooter, never outpaced Smith in TS% except when paired with Nash or Kidd).
Of course there's the difference between Nash and Rondo's shooting, but the point is, Rondo could make Smith a weapon like Marion was with Nash.
I've seen Kidd and Martin thrown out as a comparison too, which is solid, but I think Smith would be quite a bit more potent/efficient than Martin.