Good news for all of you Transformer Prime owners, as ASUS has made the Android 4.1 JellyBean update available for download for ALL users via their website. This comes just a few days after ASUS began rolling the update out OTA.
The update file, which must be side loaded to install, was posted early this morning by ASUS. You can head over to the ASUS download center and search for TF201, then navigate to firmware downloads. The Android 4.1 firmware is V10.1.2.15 and is about 318.98MB.
Note: you will need to be on the most recent official software version in order to update to Jelly Bean.