netcat can send anything over a network. In this case (after making sure the default software can't read/write to the mounts by making them ro) the contents of the internal microSD card.
On the receiving end you'd run nc 192.168.1.xxx 1234 > output_file. At a few MB/s I guess it took about 10 to 20 minutes for the whole 4 GB to transfer. You can then examine the internal filesystems using the instructions I posted
here. However, the boot stuff (u-boot and Linux image) is actually written to the first 25 MB or so, making it hard to analyze and also above my ken. We'll probably need to figure out the exact format before we can do truly interesting stuff like running Debian and a kernel with USB host/OTG support. On a related note, I'd also be interested in zram.