All the dirty details of Microsoft’s first Windows Phone 7 update, from ArsTechnica:
The updates are failing to install in two ways. For lucky individuals, the process merely hangs on step seven (out of ten); rebooting the phone resurrects it, albeit without the upgrade. For a minority of unlucky users, the process fails at step six, and corrupts the phone’s firmware. What’s worse is that for some of them it appears to be bricking the phone completely, rendering it useless.