Just a couple days after Asus shared a download link to the official Jelly Bean update for the Transformer Prime, they have now done the same thing for the Transformer Pad Infinity. Of course if you are one of the folks that uses custom ROMs then you will not have been alerted to the OTA update; however, all you need to do is download the new JB ROM below and install it the same way you have installed other ROMs in the past.
It's important to note that they have both “worldwide and US exclusive” downloads. Make sure you make the correct selection accordingly. Here's the link: ASUS - Tablet- ASUS ASUS Transformer Pad Infinity TF700T