We still have a few weeks before the release of this device, and it's already rooted. This is to be expected from a Nexus device! Anything with an unlockable bootloader is going to be super easy to root and hack! The root method is pretty simple. The only thing that may trip some folks up is the fact that you will need to have the SDK installed. Installing the SDK is not as difficult as folks make it out to be and there are plenty of guides on the web. Once you have the SDK installed it is pretty much a breeze to get this thing rooted from there. You simply copy and paste several commands in ADB. If you have preordered this device like me or if you plan on grabbing one when it releases I would highly suggest bookmarking the source link!
UPDATE: ONE- CLICK Method Now Available (No need for ADB)
Instructions and Download Via Nexustablets.net