In follow up to my question a couple of weeks ago, I finally came back to the v8 source code and managed to get it to build with Visual Studio 2013. The steps outlined in the documentation didn't work exactly.
First, I have Visual Studio 2013 and 2015 RC installed. When running the "python build\gyp_v8" step, the generated solution and vcxproj files all targeted Visual Studio 2015 RC. I had to set the GYP_MSVS_VERSION environment variable to "2013" to get the right project files and solutions to be created.
Second, I did not have python.exe in my path. I thought that the python in depot_tools would be used, but that wasn't the case. During the build, I received errors that js2c couldn't run because "python" could not be found. You need to add the path to python.exe in your PATH environment variable before running the build script.
Third, I typically build with PowerShell, but this didn't work in my case. I had to run the build script using the Developer Command Prompt for VS2013.
I hope that this helps anyone that is trying to build v8 on Windows.
Michael Collins