In regards to Marbury, I'm not sure that he doesn't stick here after this year. Even if he plays well, I don't see teams that have a young core wanting to sign him. It's one thing having Marbury on a winning team with a veteran core, but if you put him back on a losing team with a young core there is a lot of risk there.
The other aspect is that Marbury is 32 years old. His game is on the decline. So no matter how he plays, I see a lot of teams not even thinking about picking him up even if he plays well. You can rule out all the teams that he has played already because he left those teams on bad terms. You can pretty much rule out all the non-playoff teams since they wouldn't want to take on the risk. You can rule out some of the playoff teams as well (Orlando has 2 quality pgs, Lebron says no, Utah/Portland wouldn't take him, NO doesn't have money, Chicago has Rose/Hinrich, etc.)
In the end, the only competition if Marbury plays well will probably be 3-4 teams that are contenders looking for that extra boost. But with players like AI, Kidd, Bibby, Miller being free agents also, I doubt Marbury is going to be on top of their lists.