I use pfSense for my FW solution, and its developers have a second bootable configuration on the same embedded installation that can be chosen at boot (over serial console). That allows easy roll back should an upgrade go bad. My understanding (possibly wrong) is that their upgrade process copies the running slice and config to the second partition, then upgrades the second slice and sets that as the bootable slice for the next restart. Is that something that would be interesting for N4F's developers?
I also plan to suggest N4F's method of offline upgrades to them. Currently it's only upgradeable when directly connected to the Internet.
Like everyone's boss, I'm just full of ideas!

...or something!
Thanks for a great project.