Arenas, Davis and Brand opting out all have a huge affect on Maggette's ability to make money, since there's not that much out there. Going into free agency, ten teams could conceivably offer more the MLE based on cap space. The Clippers and Wizards seem to have spent their cap money on Davis and Brand and Jamison and Arenas, respectively. It's unlikely the Hawks ($7 million without Smith or Childress), Bulls ($10 million without Deng or Gordon), Sonics (over $10 million) or Bobcats ($7-8 million with Okafor's QO) will have any interest in Maggette. That leaves 4 teams: New Jersey, Memphis, Philly and Golden State.
The Nets should have around $7 million available. They might be interested in offering him a 2 year deal starting at $7 mil. This will let them have more cap space expiring in 2010, and gives them more flexibility to deal Carter. They won't offer anything beyond 2 years, though.
Grizzlies have $17 mil available, but will they care to invest it in Maggette? I think they hold onto it for next year.
Philly has at least $12 mil in cap space. They're pursuing Josh Smith, which would be interesting. If that doesn't work, they might just make an offer to Maggette. But would they offer Maggette money when they'll likely be locking Iguodala up long term at the same position?
Then comes the Warriors. They could definitely offer Maggette a lot more than the MLE, since Davis appears to be heading out of town. While they are stocked with wings, that's their style. They could make an offer, especially since their tens of millions under the cap with Davis opting out and probably leaving town.
No sign and trades, though if Davis goes to LA. LA has to renounce Maggette's right if it signs Baron. Then he's stuck either taking the MLE - in which case, we're in the same boat as everybody else - or hoping for Golden State, Memphis, New Jersey or Philly to offer him more than the MLE.