teach git-am about patch series manipulation?

Hi,

The development of packv4 is fun. Like git, patches are exchanged over email. But the series is long and sometimes I want to modify or even drop an old patch without sending 90 mails to the list. I wonder if we should teach git-am more about patch manipulation so that git am could be told to:

 - fix an old patch (like rebase's "fixup!")
 - delete an old patch (I'm guessing an empty patch with "!drop"
prefix in subject)
 - reorder some patches (how??)

I could publish my branch somewhere and ask for pull. But I'd like to see if it could be done via email only. And even if I ask to pull, I need to describe my changes manually. If I can give instructions to git-am in human-readable form, then the receiver gets my change summary automatically.