FYI - nice instructions that Jason Kridner wrote recently:
BeagleBone Black Extracting eMMC contents
http://elinux.org/BeagleBone_Black_Extracting_eMMC_contents
There are lots of ways to extract the contents of the eMMC to save off and reuse. I'm proposing a method using Buildroot and an initramfs such that you can simply drop a few files from a .zip onto a normal, FAT-formatted SD card to perform the extraction. There are several things really handy here, such as the ability to edit autorun.sh to be whatever script you want to run on your board at boot. In the archive, I only have the necessary autorun.sh for saving your eMMC content. The flip-side is provided here in the text such that you need to go through a couple of steps before you trash your eMMC.
I'll have to give this a try. Anyone else have other methods of backup and/or restore for BBB?
thanks,
drew