Could someone please explain why patching this bug isn't an option? i.e. swap out the troublesome icons and replace them with versions that explicitly allow unrestricted reuse. Hardly a radical fork. Ok, someone with time and design skills will be needed, and it'd probably reopen #68180 for a bit, but that seems fairly trivial in comparison.
Naturally IANAL, but if a product is 99.9% open source, and the remaining 0.1% serves to identify the product proper, then to me it seems fair use to include that branding wherever the rest of the product is packaged as a whole. But even if fair use might apply, inclusion of the images in Gobuntu stills seems inappropriate - there's nothing that counters the substantive point in Mark's <a href="http://diveintomark.org/archives/2007/10/18/gobuntu-has-already-failed">Gobuntu Sucks</a> post.