Apple released another iPhone 2.0 OS update and the iPhone SDK Beta 3 today. The last iPhone SDK update is just about 10 days old. Update: Reason for the rapid release of the update is the fact that the previous beta iPhone 2.0 OS expired. Developers could not continue to work on their iPhone apps.
The new iPhone 2.0 beta firmware version 5A240d is providing fixes and improvements around Microsoft Exchange support according to MacRumors.
The big Apple developer conference WWDC 08 starts on June 9th and the release of the iPhone 2.0 and SDK is scheduled for June. Ideally, the release happens at the WWDC 08.