The much anticipated Deployment Guide has been released for the Surface Pro. If you click this link you will be redirected to the Microsoft Download Center for the Surface Pro firmware and driver pack.
Then, click Download and you will be presented with the ability to download the Firmware and Driver Pack or the 16 page PDF that gives you all the details to successfully deploy Windows 8 to the Surface Pro (or both).
In order to do PXE boot with the Surface Pro, you will need to purchase the Surface Pro Ethernet adapter. You CANNOT use any other USB Ethernet adapter, it has to be the Surface Pro Ethernet adapter.