Hard links have the same problem that the new symlinks do in dealing
with sticky directories:

owl% cd /var/tmp
owl% ln /var/log/messages foo
owl% rm foo
override rw-r--r--  root/wheel for foo? y
rm: foo: Operation not permitted

Isn't the problem really sticky directories, not links?

Maybe sticky directories should keep track of who created what and use
that to determine unlink permision.

~Ken