Reality,
I think Atlanta comes out just fine in that Harrington may not figure in to their future, and Atlanta really needs something more than their current crop of (disap)point guards. Getting Marbury gives them a legitimate point guard.
As for Minnesota getting a bigger offer for Garnett? Let's see one that a team is willing to make. I offered LA's future big man, a current star level player, and their young starting point guard PLUS a pick for JUST Garnett. And if I were Minnesota, I'd at least ask for a signed confession that they had Kobe Bryant's word on a contract signing before they traded Shaq just so that they can point and say, "See! We're not the only ones doing that Joe Smith kind of thing!" in addition to everything else.
I don't think Minnesota will get as much as you think they'll get - which is why I don't think Garnett is going ANYWHERE.