Veewee on Windows Needs PowerShell Community Extensions
As it turns out, Veewee on Windows needs the PowerShell Community Extensions (PSCX) installed before you can actually export the Vagrant VirtualBox box you just created. So now the Veewee folks have corrected documentation in the form of a Github pull request.
While I am at it -- please use CMD or PowerShell when working with Veewee on Windows, rather than a Cygwin shell (Bash, etc.) You will thank me.
("In the form..." -- is this the right phrase?)