As per summary, removal?
nah, it's still quite available via google. I'd take a patch to the ebuild to direct people to alternate sites though.
uhm there is also an updated version that is based on the opensource version of quake3, not needing quake3 to be installed, maybe we could it working using the os quake3 ebuild from portage. http://www.moddb.com/mods/navy-seals-covert-operations/news/nsco-gold-gui-silent-risk google send me here http://ioquake3.org/files/mods/
Additionally I found this: http://code.google.com/p/ns-co/source/browse/#svn/trunk/nsco maybe also some information is here: http://icculus.org/pipermail/quake3/2008-April/002428.html