Anyways, I've tried most of Nexus 7 root scripts including latest Transformer Prime, Amazon Kindle, etc...etc...
The main problem with jellybeans is that root cannot be attained through /data/local as you cannot move /data/local/tmp directory as most ICS root scripts can do.
Fastest way would be to build a ClockworkMod Recovery then flash supersu zip files. But I do not have the skills to do that, but I do have the device.
If anyone needs adb pull, let me know and also let me know how to do it.