Are you not worried about: "Also be aware that this is still unreleased software and can cause severe damage on your machine. Use at your own risk!"? Should I be?
I have 64-bit OS. Am I out of luck? "Download the Go Windows 32-Bit Distribution and run the installer. As of now this guide does not cover 64-Bit installations as it causes some problems compiling the secp256k1 library."
We'll have to wait and see if they distribute binaries when the testnet comes in a little under two days. If you're unfamiliar with checking out code from repositories, I wouldn't bother with that approach for now.