Rules for commercial redistribution of NSLU2 units that use Unslung, OpenSlug or other firmware developed by the nslu2-linux community (substitute Unslung for appropriate firmware variant):
If it's Unslung unchanged firmware image (from a released binary image) and just some ipkg commands executed before delivery, then it can be called "Unslung firmware".
It must talk to the official feeds and be updateable from those feeds like a normal Unslung binary image is.
If it's a different image installed, or it ipkg updates from different feeds, then it must be called something different from an official nslu2-linux firmware name.
If it's Unslung firmware, then we consider it no different from it someone downloaded and installed it themselves. Basically, you're getting paid for the service of pre-installing official firmware for them, and everyone's cool with that.
If it's something different from official Unslung firmware, then we need to talk about support channels and such ... we don't want a variant of Unslung (mostly the same, but slighty different) confusing people on the official mailing list and IRC channels.
If it's different from Unslung, then (a) it must be clearly marked in all places (including the version string in web interface and the version string in /.unslung, but not the name of /.unslung or /unslung) as something different from Unslung.
If there are any questions about licensing of nslu2-linux firmware, feel free to send an email to "licensing (at) nslu2-linux.org".