TUAW reports that Apple-approved iPhone developers have been hit by the "Pink Screen of Death." The current iPhone 1.2 firmware distributed by Apple to developers expired at 12:01AM last night.
This device is expired. Please install a newer version of the OS.
Also, iPhone hacker Nicholas "Drudge" Penree has told TUAW that users can bypass 1.2 / 2.0 activation altogether by using the iPhone DevTeam's PwnageTool.
Barring these "unofficial" methods, affected devs will need to wait until Apple releases an updated version of the iPhone 1.2 firmware.
[u] iPhoneAtlas reports that "the new SDK build is available, but a device-installable OS update is not, leaving developers locked out from their iPhones for the time being."[u]
Editor's note: Pwnage to the rescue? That's rich irony...