Hurd kernel is already usable and beyond Hurd Debian distro http://www.debian.org/ports/hurd/index.en.html , we have ArchHurd http://www.archhurd.org/ .
We read in wikipedia about Hurd:
"GNU Hurd (usually referred to as the Hurd) is a computer operating system kernel designed as a replacement for Unix,[1] released as free software under the GNU General Public License. It has been under development since 1990 by the GNU Project of the Free Software Foundation.
GNU Hurd consists of a set of protocols and server processes (or daemons, in Unix terminology) that run on the GNU Mach microkernel; together they are intended to form the kernel of the GNU operating system.[1] The Hurd aims to surpass Unix operating systems in functionality, security, and stability, while remaining largely compatible with them. The GNU Project chose the microkernel server–client architecture for the operating system, due to perceived advantages over the traditional Unix monolithic kernel architecture.[2]" http://en.wikipedia.org/wiki/Hurd
Debian and Arch are already working on ports with Hurd kernel, as is Mageia community in the future could have a distro port to Hurd too.
If the Linux kernel be monolithic is so good, think about the possibilities with the Hurd kernel is much more advanced because it is based on a microkernel and independent modules to manage the machine.
Mageia Hurd, the future?