Last Updated: June 5th, 2012
Update: BurritoRoot may not work on version 6.0 firmware. If you're having trouble, update your firmware and try again.
On the historic date of December 20th, 2011, Amazon pushed out software version 6.2.1 to its Kindle Fire. The update was fairly minor -- its main additions had to do with improved scrolling and WiFi passwords -- but it brought about one devastating change: it broke all previous methods of root.
Last Updated: December 7th, 2011
Update #1: Well, that was much faster than anyone expected - RIM has already released the patch for this exploit. The good news is that the patch isn't yet available in the 2.0 Beta, but you can bet that it will be rolled into the update before it hits the masses in its final form. If you happened to accept the update on the current version and still want to give this exploit a try, then you can always downgrade the OS.