Amazon has released a new update for the Kindle Fire that brings it up to version 6.2.2. The new version brings a new feature to the tablet but we should also warn here that it also breaks root for those who have rooted their new tablet.
The new feature it brings to the tablet includes the ability to browse full screen when using the Silk browser. Other than that, nothing has been spotted yet.
For those interested in rooting the Kindle, it might be best you hold off updating at the moment as there is no replacement for BurritoRoot which handled rooting on the last version. Although it might not be possible to jailbreak the device now, it could be in the next day or two, so it's up to you if you want to risk waiting and assume it can be rooted, or if you take the safer path and hold off updating until a root has been confirmed. We'll leave that choice to you.
Upgrading can be done manually which requires you manually download the file and place it in Settings > Device > Update your Kindle. For those who want to wait, it should be made OTA shortly. Full details of where to get it can be found in a thread over at XDA Developers.