For several months, I've been tagging attachments I receive on e-mails with the tag "&email," the sender, the date it was sent, and any other tags I want (all via an AppleScript folder action), and it's worked great. Quicksilver makes it really easy to, say, find all the attachments I've been sent from any particular coworker, and when I change the filename, the metadata stays intact. Beautiful.

The problem -- now I want to actually archive my emails as text files. And I want all the files on my machine currently tagged with "&email" to be retagged as "&attach."

Is there any easy way to retag many files?