.21 TF201 ROOT IS HERE! CLIFF NOTES

We are going to revert to .15 then Root, then utilize OTA Rootkeeper, then update back to .21 (utilizing OTA update not downloaded zip!).

Follow this android genius' directions here: http://forum.xda-developers.com/showthread.php?t=1622628
Execute Method #2.  Only you are responsible for damage to your device. 

Cliff Notes or click here for full instructions to root .21:
1) ADB Drivers can be tricky I found success with Vipers'  I needed to update the drivers for ADB and the TF201
2) Extract, extract and download proper old firmware from ASUS.com to root of device
3) Follow Method #2 above commands
4) You may want to do some cleaning when done. 

As a sidenote I'm really tempted to stay on Honeycomb.