"iPhone OS 2.1 beta 3 is now available and is to be used for testing only. View the Pre-Installation Advisory for iPhone OS 2.1 beta 3, Readme, and Release Notes before installing the new versions of the iPhone OS and SDK. As a reminder, pre-release software is Confidential Information and is subject to the terms outlined in your Registered iPhone Developer Terms and Conditions with Apple."
Of course, we don't know what's been changed in this release. Note that iPhones updated to OS 2.1 beta 3 cannot be restored to an earlier version of the OS, and apps developed a beta OS 2.1 cannot be submitted to the App Store.
Thanks to everyone who sent this in.