All the following is based only on a first, and quick glance only.
We may want to have a look at Virtual Square / View-OS, and evaluate in which
ways this is related / implemented / implementable / usable / useful in a Hurd
environment, and even 
strive to collaborate with them.
I found this project very much by chance: on LinkedIn, they posted a proposal for DevRoom on Virtualization Technologies for FOSDEM 2011. LinkedIn sends out such posts in very opaque emails from time to time (probably they'd look less opaque with a HTML mail user agent), and I even bothered to have a look at it, and follow the link to the web page, and not delete it straightway.
So, I had a quick look at the project:
This seems to be an amalgamation / combination of various virtualization
mechanisms / projects / ideas. Virtualization is here meant in a broad sense,
including file system namespaces: our chroot / settrans --chroot;
networking configurations: our pfinet override stuff; system configuration:
subhurds?; current time, devices: likewise?; executable interpreter: our exec
server override stuff; "stat" virtualization: fakeroot; etc. -- They seem to
do a lot of stuff that we also try to do / could do / can do.
In fact, this looks a bit like they're trying to bring some more of the Hurd's concepts over to Unix / Linux, more than only the usual VFS stuff (translators / FUSE).
Perhaps start reading with the slides linked below.
Renzo Davoli, Virtual Square, 2005
Renzo Davoli, Michael Goldweber, View-OS: Change your View on Virtualization, Proc. of Linux Kongress, 2009