Andrew,
I've tried to delete one host with its management processor and discover it again - nothing has changed. This host was freshly installed ESXi (HP customized image). But I've found one interesting thing:)
If I select Quick Launch -- Manage Communications, select this server and press update button - "WBEM Health Inclusion Status" link shows up after some time:) BUT...
If I select this server's management processor and press on "Identify Systems" link - when task finishes "WBEM Health Inclusion Status" link disappears again:) I don't know what to think:)