It turns out there's a group called the world agile certification board that is going to, ta-da, certify agile developers and testers and such. You can google them; I won't link to them because I don't believe they need any more google juice.
I thought about writing a long reply, but it turns out there are two:
Elisabeth Hendrickson did a thoughtful reply earlier in the week, and, more importantly:
Tom DeMarco summed up my thoughts on certification over a decade ago in the CutterIT Journal.
You can read it here.
I'm taking a hard-line here, but I'm still interested in your thoughts.
UPDATE: I've been thinking about the craft of writing and what makes one qualified to write a good book, in the context of certification. In other words: What can you learn in a three day writers workshop? What can you learn over the course of three years writing a blog? What about ten years? I can blog on it if you'd like; let me know.