According to MacRumors, the 2.2 firmware beta has been seeded to developers for testing. No new features have surfaced yet, though one interface change in Safari has been noticed. In 2.2, the Google search bar is now visible next to the address bar at the top of the screen - see here for a screen shot.

No reports of the push notification service previously promised have surfaced, though many iPhone users and developers are anxiously awaiting this feature.