After some discussion in #gentoo-dev upon seeing the Gentoo review in the URL, those of us present came to the conclusion that a samba USE flag on the gnome metabuild to pull in gnome-vfs-extras would be a good idea. This would help Gnome to "just work" even better than it already does, IMHO. Neither Obz nor I was aware of any documentation stating what's needed to get samba working in nautilus, so if the USE=samba isn't done, there should probably be at least some postinst info on gnome. Obz suggested I file a bug to get some more feedback.
sounds reasonable, although gnome meta was initially meant to be the exact gnome desktop release, we already moved away from that a bit. What is the current stability of smb support in vfs-extras (i have no experience with it) ? On the other hand, gnome-vfs-extras was not always just samba support and that might change again in the future. It may bring in more than just samba deps.
One possibility if more "extras" are added is to split them into separate packages, gnome-vfs-samba, etc. The stability seems fine from a brief test, I'm able to browse networks and computers with no trouble.
gnome-vfs-extras dep trough samba USE flag has been added to gnome-2.4.1 meta for now. The exact definition of what gnome meta is should be discussed soonish though.