We've always explained that we're based on Gentoo, and its the way you upgrade your system, you use gentoo's emerge/portage system

I think that should be explaination enough for any contract hunter...I think
Any lawyers, official ones please, that know better and will give advice pro bono may send me an email if otherwise.
I'm pretty sure the only big deal would be if we tried to repackage and forked off the main gentoo line. What we're doing is just taking the minimal gentoo install and building it all the way up for the user already and offering it.