iPhone OS 3.1 Seeded to Developers

iPhone OS 3.0 is only 2 weeks old, but Apple already seeded the next version 3.1 to developers (Build: 7C97d) as well as the associated SDK (Build: 9M2736a).
The iPhone DevTeam will have to work as the update 3.1 is modifying the baseband of iPhone 3G and 3GS.