Now that I'm running the RTM of Windows 8 on my dev machine, I can get back to writing my first app. I want to make sure it works on Windows RT, so I'll be testing on my Surface.
The first step is to install the ARM version of the remote debugging tools (from here) on the Surface. This is a fast download and install. The next step is to run the remote debugging monitor on the Surface. The first run required me to save the initial settings. After that, the Surface was available as a remote target from Visual Studio on my dev machine. Running the app for the first time (and every 30 days after that, at this point) causes the Surface to request a developer license so that the app can run. Without this license, the app won't run (the same is true of apps deployed for testing on the dev machine).
After all of this, the app got deployed to my Surface and ran. That's it, simple, quick, and painless. Further testing should be even quicker since the tools are already installed.
See also: Running Windows Store apps on a remote machine (via Microsoft)