Well, as I stated in that other thread, I really don't see the need for additional prefixes or sub-forums. The models all do the same things; the only difference is whether they do it using a physical keyboard, a virtual keyboard, or a 5-way controller. The only real difference I can see is the X-Ray function on some of the newer models.
I can understand why the Kindle Fire would merit its own sub-forum. It's as different from other Kindles as night and day. It's a tablet with a backlit screen that runs apps. But the other Kindles are extremely similar. Outside of the X-Ray function mentioned above, which I doubt many owners will use with any regularity, and one or two other quirks such as the 3G Touch needing a WiFi connection to surf the Internet, they're all basically the same device.