The sshd uid added to my system was > 1000, making it a 'user' and not a 'system' uid. The sshd uid should be < 1000 (preferably less than 100), otherwise it could be exported via NIS.
IMO the UID and GID should be 22, following the tradition of mapping port numbers into UID and GID. I don't see any problem with /etc/passwd, but in /etc/group GID 22 is taken by group 'games'... Doh!
22 is fine with me, just so long as it is < 1000 and (preferably), 100 as well.
http://bugs.gentoo.org/show_bug.cgi?id=4193
Afaik, the "games" group isn't being used by any of our ebuilds, and probably not by any of our users. It shouldn't be difficult to switch to "sshd" if we need it.