As of today the tar-ball for Debian GNU/Hurd that Marcus Brinkmann made over the years have been discontinued in favour of Jeff Baileys crosshurd package. So to install Debian GNU/Hurd from now on, please use the crosshurd package avaiable in the Debian testing archive.
Jeff might provide an automaticly generated tar-ball for people that don't use a Debian system. So if you are not using Debian you have two choises, Philip Charles CD's or wait untill Jeff (or someone else) provides tar-balls created by the crosshurd package. Cheers from Marcus' minion