So, I'm a little bit unclear about the exact implications of this; has anyone gotten a working bootloader for the A5A working because of the Angstrom firmware, or is that just the derivative 'next step' now that this has been released? Or is it something the 'DualOS' firmware provides?
I'm really interested in tinkering with the Angstrom stuff, but I'd like to do it when I can run both 'OSs' on my device at once (so one partition can be for linux messing, and the other for a functional PMP/IT)...
The Dev firmware provides the boot loader, the angstrom distro is just a disk image stored on the drive that the A5A boots.
The next step is editing the disk image to get something else, like AOSP to boot.
After switching between the dev and official firmwares a couple of times, I can say it doesn't touch your media on the disk and will not affect your installed apps and settings. The Archos 'first run' wizard runs on the first boot back in the official firmware, you can just say no to installing the bundled apps and it carries on happily.
Unless you are trying to get something else booting on the A5A, Angstrom isn't going to do much for you. It is a 'proof of concept' to show you how to get things going. It's almost impossible to use with the touch screen and there isn't really much on there that most official firmware users would see any use in.