I would like the ability to do something similar to the CC field, i.e. you could add or remove some values without altering other values already set for that field. So if bug A currently has values "foo, bar"; bug B has "foo" only; and you want to add "baz" to both bugs but leaving values already set alone (i.e. not overwriting them), you should be able to do so.
Bugzilla 3.2 is now frozen. Only enhancements blocking 3.2 or specifically approved for 3.2 may be checked in to the 3.2 branch. If you would like to nominate your enhancement for Bugzilla 3.2, set the "blocking3.2" flag to "?", and either the target milestone will be changed back, or the blocking3.2 flag will be granted, if we will accept this enhancement for Bugzilla 3.2.
We are going to branch for Bugzilla 4.4 next week and this bug is either too invasive to be accepted for 4.4 at this point or shows no recent activity. The target milestone is reset and will be set again *only* when a patch is attached and approved. I ask the assignee to reassign the bug to the default assignee if you don't plan to work on this bug in the near future, to make it clearer which bugs should be fixed by someone else.