I wonder what "Testificate" means, if anything at all. It's probably some weird term Notch or Jeb or somebody made up as a quick way to reference them in the code, but I'm kind of thinking, since they look like they might be judges, that maybe "testificating" might be part of a legal system in a well-developed NPC social structure. Something to think on.
Edit: Just watched some YouTube vids showing off some new Nether content, including the two new monsters and NETHER DUNGEONS!!1! Jesus, I hope I get a faster computer soon, because I bet combat is suddenly going to be much more fun than it has been for pretty much all of Minecraft's existence until recently.