The new Apple TV can be jailbroken (as it runs a modified iOS 4.1 firmware) with the SHAtter exploit, then you need to save your SHSH Blobs on your Apple TV. Saving your SHSH Blobs allows you to downgrade your firmware to a previous versions. This is important if you accidentally update to a firmware version that cannot be jailbroken.

Note: It is not known, whether or not you will be prompted to update your firmware on the new Apple TV, or it will be carried out automatically. This makes it even more important to save your SHSH blobs for your Apple TV, so you can downgrade if needed.

[How To] Save your SHSH blobs on Apple TV :

1) Firstly, download TinyUmbrella ( Mac/Windows/Linux ) here.

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2) Launch TinyUmbrella. Now connect your Apple TV to your computer with your microUSB cable.

3) Once it is connected to your computer (make sure iTunes is not running), select the Advanced Options bullet and your ECID number should be displayed (this is a unique identification number). Once your ECID number is displayed, select the Cydia option from the dropdown list (as shown below). 


4) Click the save my SHSH button and TinyUmbrella will save your SHSH Blobs for your Apple TV.

5) Done.

Feel free to ask your queries in the comments section below.