[Update 2013-01-23 18:35 GMT - turns out there are a couple of Persona features we still need to be absolutely certain that this is a good thing. The change has been reverted until we've got those. Sorry for any confusion.]
In April last year, we enabled Persona logins on bugzilla.mozilla.org using a Bugzilla extension I wrote. However, we restricted this login method to low-privilege accounts only while Persona and the extension both matured.
I’m pleased to say that, as of now, unless you are a member of the administrative Bugzilla groups “admin”, “editusers” or “editgroups”, or the “legal” group, then you can now use Persona to log in to bugzilla.mozilla.org :-) In particular, this means all Mozilla employees and security group members can now log in this way.
Make sure you use the correct email address; if you pick a different one to your usual one, Bugzilla will auto-create a Bugzilla account for it.
If for some reason you want b.m.o. not to accept Persona logins for your account, you can do so; file a bug to have your account manually added back to the “no-browser-id” group.