A less than perfect workaround is to use 'easy_install-script.py' instead of the
executable.  I believe using the script requires that the .py file extension is
associated with the appropriate python installation, or that the script be run
explicitly from the correct Python installation.  e.g.
"C:\Program Files\Python26\Python.exe" "C:\Program
Files\Python26\Scripts\easy_install-script.py" <your options>

Not the easiest workaround, but at least enough to get by until someone has time
to build a 64-bit version of setuptools.