We have some more details on the new Kindle Fire update that is available. A few of these were what we already knew about the update, but their is more added to the list of fixes and improvements:
  • Enhances fluidity and performance
  • Improves touch navigation responsiveness
  • Gives you the option to choose which items display on the carousel
  • Adds the ability to add a password lock on Wi-Fi access.

It looks as if Amazon is listening to their customers. These fixes don't address all the complaints about the new tab, but they go pretty far to deal with the biggest issues. If you want to get the update, there are a couple of ways. First, you will want to check to see which version you currently have, in case you already received it. You can do that by tapping Quick Settings > More > Device. If it is 6.0, 6.1, or 6.2, then you should get the update. Here's a quote from Amazon's website with instructions for an automatic update or a manual one:

To update your Kindle, ensure you are connected to a Wi-Fi network and that your battery is fully charged. Tap the Quick Settings icon in the upper right corner of your device, then tap "Sync." The software update will automatically download in the background and will be applied once download is complete and the device is asleep.

If you'd like to manually download and install the software update on your Kindle Fire, follow the instructions below. Please note that you'll need a USB cable (sold separately) to transfer the update to your Kindle Fire.
Download Version 6.2.1

Here's how to download the Kindle Fire software update version 6.2.1 and transfer it to your Kindle Fire via USB:

Determine your software version: Tap the Quick Settings icon, tap "More," then tap "Device." If your System Version is "Current version: 6.2.1" you are running the latest software. If you see a System Version other than "Current Version: 6.2.1," please proceed with the steps below to update your Kindle Fire to the latest software.

version

Download your software: Click on the link below to download the software update file directly to your computer:

Download Software Update 6.2.1
Transfer software to your Kindle: Turn your Kindle Fire on and unlock the screen. Then connect it to your computer using a USB cable (sold separately). Drag and drop the new update file from your computer to the kindleupdates folder on your Kindle drive. (The drive is typically displayed as a "device" icon).

Monitor file transfer and disconnect: Check your file transfer progress to ensure the file transfer to your Kindle Fire is complete before disconnecting. After the file has transferred successfully, tap the "Disconnect" button on your Kindle Fire screen to safely disconnect your Kindle Fire from your computer. Disconnect the USB cable from your Kindle Fire and your computer.

Start the software update: Ensure your battery is fully charged. Tap the Quick Settings icon in the top right corner of your screen, then tap "More..." then Device. Select "Update Your Kindle." (This option will be grayed out if the most recent update has already been installed or if the file transfer was not successful.) Your Kindle Fire will restart twice during the update. After the first restart, you will see the Kindle Fire logo on the screen.

Once the update is complete: The Device screen will display "Current Version: 6.2.1" when the update is complete.

If you cannot successfully update your Kindle Fire software using the instructions above or encounter any difficulty with your software update, please contact Kindle Support by clicking the "Contact Us" button in the right hand column of this page.
Source: Kindle-FireForum via Amazon Kindle Fire Support