Here are the step by step instructions on how to flash the Galaxy Tab 10.1 Jelly Bean Android 4.1 ROM. The steps are pretty easy once you have ClockworkMod installed and even that is not too difficult.
There is already an Android 4.1.1 Jelly Bean ROM available for the Galaxy Tab 10.1. I am loving the continued development for a tablet that is over a year old now. The ROM is in an Alpha version and is classified as experimental. Many things do not work like the camera, audio, and hardware accelerated video.