Hi there! Yes, there are still gentoo machines out there running libexpat-1, and I am upgrading one now. I survived several of those upgrades yet, but those were PCs I had better access to, and where a huge revdep-rebuild was no big problem.
But this machine here is slow, and I do not have powerful distcc hosts for it. And it is powered off in the night. But it should come up back and be able to be used. Couldn't I just save /usr/lib/libexpat.* before upgrading libexpat, start revdep-rebuild, and put the old libraries back, so all applications stil have their libraries until revdep-rebuild has finished?. Wonko