I upgraded my Android Developer Phone to the latest 1.6 Donut firmware today. I have been using Cyanogen’s custom firmwares up to this point. I wanted to maintain root access so I grabbed the modified version from the XDA developer forum. It comes as two files: one is the rooted base firmware and the other is an extra set of root tools for tethering and other fun. I copied both files to my SD card without renaming them.
I rebooted into recovery mode. I’m using Cyanogen’s 1.4 recovery image which lets you flash any image without renaming it. I performed a wipe and then flashed the new image. After a reboot, the phone came up as a fresh install. The data connection wasn’t working so I used the debug shell to force the wireless options to open and setup the WiFi connection. Data wasn’t working since I had forgotten that I needed to add the AT&T APN by hand.
After that, I installed the expansion pack. I rebooted to recovery mode and flashed it. When the phone rebooted, it came up as a black screen. The firmware instructions warn that this is a possibility and I reformatted the EXT2 partition on my SD card as they instructed to fix it. The formatting instructions can be found here and you can do it from the console in recovery mode.
Donut definitely feels faster and with every upgrade they tweak issues like the camera which is much better now.