Sorry for the suspense guys
I didn't want to release incomplete code.
Here's a more-or-less complete version which allows you to list the files on the device and download them.
It needs Python with ctypes package and uses dlls from Connect software. So the best way to get it running is to drop the file in "\Program Files\Sony\CONNECT Reader\Data\bin".
To list the files:
ebook.py ls <dir> [-R]
-R means "list recursively". I disabled recursion for /dev and /proc subtrees since that can lead to infinite loops.
E.g.:
ebook.py ls /
ebook.py ls /etc/ -R
To download files:
ebook.py get <path>
E.g.:
ebook.py get /Data/tmp/info/model
ebook.py get /etc/init.d/
Be careful when downloading "files" from /dev and /proc, some of them has no EOF and the program reads infinitely.
So far I only had to reset the unit once so there shouldn't be much problems, but as usual: USE IT ON YOUR OWN RISK.